Hepatitis D, and hepatitis D virus (HDV), and are classified into delta hepatitis virus, is a disease caused by RNA viruses of the sheath small circular. Since it can be dispersed in the presence of hepatitis B virus only (HBV), and ideas E HDV subviral satellite B, C, and D: It is one of the hepatitis virus five known. Transmission of HDV, it may be caused by one of the co-infection and background (superinfection) carrier status of hepatitis B or chronic hepatitis B or HBV (superinfection). Compared to the infection of HBV alone, co-infection and co-infected with HDV results in complications more serious. The complications of these, likely to develop liver failure, the rapid progression and acute infection cirrhosis of the liver, an increased risk of liver cancer in chronic infection is high. In combination with hepatitis B virus, D-Shaped hepatitis has a high mortality rate of all HCV infection of 20%.

Receptors that recognize HDV human hepatocytes has not been established, it is believed to have an outer layer of single, two viruses, is the same as the HBV receptor. HDV to recognize the receptor N-terminal domain by a large HBs antigen, hepatitis B surface antigen. Mapping by mutagenesis in this region, the amino acid residues constitute 9-15 receptor binding site is shown. Move nucleocapsid to the nucleus by the signal from the nucleocapsid that does not contain the RNA polymerase to replicate the viral genome, HDAg makes use of the RNA polymerase of the cell the virus after the introduction of liver cells, the virus is uncoated. First, the addition III RNA Pol II, and RNA polymerase I, generally shown to be involved in the replication of the HDV RNA using polymerase II as a template DNA and mRNA are produced now.

Therefore, when using the HDV RNA polymerase II during playback Indeed, the RNA-dependent polymerases such, become pathogens only animal known to use a DNA-dependent polymerase. Structure of the rod-like as is the cause, RNA polymerase dealing with RNA genome is collapsed, the RNA genome of circular double-stranded DNA-inch, polyadenylation and the anti-genomic RNA round additional three forms of RNA is performed linear anti-genomic RNA framework of HDAg because it is the mRNA containing an open reading. Synthesis of genomic RNA while went to nucleoplasm mediated RNA polymerase II, the synthesis of anti-genomic RNA occurs in the nucleolus mediated RNA polymerase I. HDV genomic RNA is first synthesized as a linear RNA containing multiple copies. Antigenome RNA genome and comprises a sequence of 85 nucleotides that act as a ribozyme that cleaves the RNA monomers linear independent. Then, these monomers are coupled to form a circular RNA. There are eight reported genotypes of HDV to changes of unknown cause in the pathogenicity and geographical distribution.

Significant difference does not produce virus-like protein between the HDV and viroids, it is that HDV, protein, i.e. that HDAg that are known. Two forms, it is the small HDAg of 24kDa and 27kDa large HDAg. N-terminus of the two forms is the same that additional amino acids 19 is different to the C-terminus of the large HDAg. In general, both isoforms were produced in the same reading frame containing a UAG stop codon at codon 196 that generates HDAg slight. However, the termination codon of change UCG -1 large HDAg editing adenosine deaminase of cellular enzymes to allow production,. Has 90% sequence identity, two proteins of these different roles during infection. By entering the nucleus and is produced in the early stages of infection, HDAg-S supports the viral replication. HDAg-L, on the contrary, is produced during the later stages of infection, it acts as an inhibitor of viral replication, assembly of virus particles is required. The RNA is edited by cellular enzymes like this is to adjust the balance between virion assembly and replication of the virus, it is important for the viral life cycle.

Without encoding the protein product of any of its array long viroids, there was confusion on how can induce the symptoms of plants. The evidence, I believe that RNA silencing is involved. First, changes in the viroid genome will be able to change its virulence dramatically. This reflects the fact that siRNA all generated that has a base pair additional less targeted RNA. Second, siRNA corresponding to the sequence of the viroid genome was isolated from infected plants. Finally, transgenic expression of non-infected hpRNA of potato spindle tuber viroid is, develop the symptoms of viroid well as all related. These data were reproduced in a double-stranded RNA intermediates, such as viruses, they show that after instructed by the enzyme Dicer, when it is cut into, siRNA is loaded into the RNA-induced silencing complex are. This is what causes the symptoms viroid classical containing sequences capable of complementing the pairing base to inhibit translation or induce degradation and messenger RNA own factory really viroids siRNA.

RNA has been identified as a sub-viral RNA, viral satellite RNA, viroids, human hepatitis delta virus and satellite (HDV) is a infectious pathogens known minimum. Encoding (HDAgs) viral proteins two HDV genome, the circular genome of single-stranded small, negative sense RNA containing a self-cleavable motif, and is configured open reading frame from (ORF). HDV requires a complex distribution of the surface antigen of hepatitis B virus (HBV), a virus. Small is replicated autonomously in the host plant and unencapsidated, single-stranded circular RNA encoding viroid is (~ 400 NT). Based on the presence or absence of (chloroplast and nuclear), viroids are classified into two families of the subcellular localization conserved regions and ribosome hammer. I own the code for a protein of genes required for the replication, satellite does not depend on the helper virus for its propagation. Both satellite and satellite virus nucleic acid contains the satellite. Satellite virus is composed of capsid single-stranded RNA genome by the protein encoded by satellite. Satellite nucleic acid comprising a satellite RNA of single-stranded RNA satellite subset of satellite RNA and double-stranded. Double-stranded RNA wrapped in a coat of satellite assistant viral proteins. (Also known as a satellite RNA viroid similar) the satellite RNA satellite RNA circular protein, a small linear encoding major satellite RNA: by encoding the protein capsid, single-stranded RNA genome, the three groups I have a satellite that is not classified.

I form the main part (ie, associated with viroid, vHDV, and RNA satellite RNA) of the database section of the one associated with the sub-viral RNA sequences. Their families, are indexed according to the species or genus in the classification system on the basis of criteria established by the International Commission on (ICTV) classification of the virus RNA mutants of all. Once appointed by the ICTV, certain types of use are classified based on sequence similarity it. If any, various agents, RNA, redundant thereof, sequence variants, and the number of size distribution of them is calculated based on the secondary structure of the exemplary embodiment, the family, designated by point database ICTV I choose to lead-point representation of the full name of the code of the type that is. For a particular type of each of the RNA, users can have access to a complete list of links to sequence identical to the sequence variants. Array of identical, might mean consistency improved fitness of in vivo for a particular option. Further, a link to a specific RNA motifs specific is shown in each mutant. From this point, it is possible to individually or in groups, to select the sequence, the user displays them in a different format using analysis software further to the user. In order to display in HTML format records these causes, it is dealing with subviral server directly using (see below) bioinformatics various tools, or possible, to facilitate the transfer to another program, the raw It is stored in a text of.

For retrotransposon “duplicate input mode, you can increase the size of the genome using an RNA intermediate to increase the copy number of elements rapidly. Similarly DNA transfer factor (transposon class II), the retrotransposon array of. insertion site within the gene or two that can cause mutations by insertion near the replication machinery, because they are maintained transposed since, further, mutations induced by retrotransposon, relatively stable . retrotransposons are is performed by reverse transcriptase encoding a retrotransposon second step of forming a. DNA to go back to the DNA, to copy the RNA is itself subsequently integrated back to its potential genomic transpose and survival retrotransposon. host genome to a can, between the host and retrotransposons and a retrotransposon and host could be regulated by both retrotransposons factors hosted coded Top insertion mutation results and to understand how to have evolved a mechanism for adjusting the characteristics of transposition “host and retrotransposons. genome to avoid the harmful effect on the relationship that existed millions of years to In order to optimize the viability of the other, it is still in its infancy. Retrotransposon most will not be able to retrotranspose longer by mutations that are very old, stored.

LTR retrotransposons are, have, a direct LTR’s in the range of 5 kilobytes of size more than 100 bp of ~. Retrotransposon LTR is group based on both the order of the gene product to classify (Metaviridae) such as TY3-Gypsy In addition, (Pseudoviridae) as TY1-copier, and encoded degree of sequence similarity of their are as Pao-BEL-. TY3-gypsy group retrotransposon and TY1-copier, are found in (to several million copies at the maximum haploid nuclei) copy number of the genome of the plant animals, fungi, and protists are often in general. The Pao-BEL like elements found in animals previously. About 8% of the human genome, and approximately 10% of the mouse genome is composed of transposon LTR.

It is a group of genetic elements present in large amounts in the genome long dispersive element eukaryotes. They are transmitted to the RNA using RNA polymerase II promoter, which is disposed inside the line. Line endonuclease (ribonuclease H, for example) is also the number of lines of code and code, for the reverse transcriptase. It has a high specificity for the RNA from the line other RNA, reverse transcriptase performs the DNA copy of the RNA it may be incorporated into the genome of the new site. Code endonuclease can be a type (restriction endonuclease as) AP type or REL (apurinic / pyrimidine) by non-LTR retroposon. R2 group of elements has a type REL endonuclease indicating the insertion of site specificity.

‘The UTR, promoter sequence contains three’ UTR containing Polytail 5 and polyadenylation signals (AATAAA) and. Itself is moved to the copy (of moved by the cut-and-paste mechanism, as is the case class II transposon such instead) (Sines and LTR retrotransposon transposon, of electrons. Classes I and other) the line They expand the genome. For example, the human genome contains about 500 lines 000 in about 17% of the genome. Of these, 7000 are a small part of overall length, retrotransposition is possible. Be associated Interestingly, retroposons of LINE-1 genome particular is actively transcribed it recently, essential to create chromatin local environment and closely nucleosome associated with LINE-1 RNA has been shown .

RNA molecules, 5S ribosomal RNA, and short scattering element is a short DNA sequence that represents a small nuclear RNA of other transcribed reverse transcription by RNA polymerase III of the mRNA of the first. Encodes the reverse transcriptase of functional protein, Sines is not dependent on the elements of the mobile phone other for transposition. Sines most common of primates is called aluminum sequence. Does not include a code sequence is approximately 350 base pairs, with a restriction enzyme, alloying elements, can be recognized by AluI (name). Sines comprises about 11 percent of the human genome about 1.5 million copies. It is believed that “junk DNA” Historically, a recent study in order to develop new features, in some rare cases, cine lines and two, it is incorporated into the new gene I shows. Distribution of these elements, have been implicated in cancer and hereditary disease specific. Sequence analysis of Alu subfamily in humans, shows a (recombinant) component Mosaic However, experimental evidence is lacking. The frequent exchange of a sequence of retrotransposition in eukaryotes Entamoeba histolytica primitive, has been reported, this leads to a mosaic pattern of the SINE sequence.

Protozoan parasites that affect humanity deeply represents malaria, toxoplasmosis, amoeba, Giardia, such as leishmaniasis and trypanosomiasis, a very diverse group of organisms. Many aspects that need to in spite of the significant impact of these parasites, open and how mechanisms of pathogenesis these organisms to survive in the host is left. Coupled with the increased availability of the genome that have been sequenced, RNA interference (RNAi) was discovered 13 years ago just in organisms not subject to classic genetic approach in particular, it is a very simple gene function is an analysis. In this case, we put a special emphasis on the use of the post-genomic tool to determine the current status of RNAi in the study of parasitic protozoa.

Affect the human race, in those caused by parasite malaria and disease, many, such as Leishmania major, for causing a high incidence of morbidity and mortality, and low-impact mainly, they or Africa South America trypanosomes, there is a great interest in public health – income populations in developing regions of Africa are often limited, Asia, North America, South American medical resources. In addition, affect the quality of life deeply, parasitic diseases have a major impact on the economic development of the whole country. I think usually, parasite infection and is more common in developing countries, but they also are popular in developed countries, trichomoniasis, toxoplasmosis and Giardia, have a significant impact in the United States. Chemotherapy is a powerful weapon against these parasites, the success of this approach is impaired by extensive resistance to some of the most effective drugs, including chloroquine in the treatment of malaria, have been developed so far are. Therefore, development of new treatments is urgent based on the evaluation and identification of drug targets potential.

Double-stranded RNA is (dsRNA can), a process called (RNAi) RNA interference found exclusive 1998, has a great impact on the side of the new winding eukaryotes that triggering the suppression of gene expression gene function in organisms that do not qualify for genetic classical approach particularly it had, which facilitates the analysis significantly post-genome era. Further, 20 and 30 nucleotides, antisense RNA, by opening a new world of small regulatory RNA, an enlarged still can be used as a therapeutic agent for small RNA, recognition that results in a small suppression of gene expression, large I want to improve the human disease that generated the expected.

In this section, we provide a view of the latest of RNAi pathway in parasitic protozoa, to discuss the usefulness of current and potential of RNAi as a tool. Not only chose to concentrate in organisms is not only important in terms of human disease, it is, we, and most, continue to be the subject of intense research in many laboratories around the world Importantly, of the RNAi to be examined for the presence of. (Wasting disease similar to sleeping sickness) pathogen of sleeping sickness, and these cruise that causes Chagas’ disease in South America, including T in the nagana cattle and humans in Africa (i) kinetoplastids Trypanosoma, sub-Saharan,, , agent of immunodeficiency New World Leishmania parasite old and causing various forms of world leishmaniasis, toxoplasmosis of (II) apicomplexans Plasmodium falciparum, of, the most deadly of the malaria parasite Toxoplasma human of the causative agent (IV) is the dysentery amoeba of diplomonad intestinal Giardia, causes a Giardia known as Bieber Fever serious threat, also (III) amoebozoa Entamoeba histolytica, and to individuals. Four groups of these organisms have a life style radically different if you are far away from each other evolutionarily.

Macrophages, trypanosome blood propagation as infection in immune cells of other living in phagocytosis lysosomes they Leishmania species that live in and T parasitophorous vacuole obligate intracellular parasite is Toxoplasma species and malaria. Giardia and dysentery to grow outside the cell in the gut environment, On the other hand, T. Cruise, will infect a variety of cell types in the vacuole of transition parasitophorous which is formed between the cell infiltration of the cytoplasm. Importantly, and that they are adapted to grow in laboratory techniques described above. All protozoan parasites have been developed for gene manipulation, their genome or is, is a process sequence.

The main function of the factors regulating the elongation phase 7SK human control P-TEFb, a transcription. Kinase activity when P-TEFb coefficient of 7SK human origin is inhibited. You can release including P-TEFb, a protein BRD4, a bromodomain from HIV or beta Tat or 7SK human origin. In this release, result in structural changes in the discard HEXIM 7SK RNA. Stabilization hnRNPs lacks the HEXIM and P-TEFb complexes. The P-TEFb function after gene re-isolated 7SK people from a particular by an unknown mechanism. I is characterized by both the Drosophila and human human 7SK.

Human 7SK RNA is a generation rich 331 NT nuclear transcription by RNA polymerase III. Join HEXIM1 / 2 of 7SK RNA is the protein inhibitor of these P-TEFb of (positive elongation transcription factor B). P-TEFb is required for transcription elongation of RNA polymerase II. Leads to the activation of P-TEFb, retention and transfer, 7SK RNA is released from between P-TEFb/HEXIM/7SK complex physiological stimuli such as cardiac hypertrophy. Subset of (hnRNP of) Freed 7SK RNA fellow heterogeneous nuclear ribonucleoprotein. 7SK RNA, which is stored in vertebrate evolution, the same family has been found worms, insects and mollusks genome. The folding pin 7SK RNA several serving as a platform for the specific binding protein. It is stabilized by end monomethylated ‘La related binding proteins, LARP7 its three and three phosphate groups 5’ thereof. Characterized to regulate transcription of ncRNA paradigm best 7SK RNA probably.

Deletion analysis was performed human 7SK RNA gene, the contour of the major areas in vitro transcription by RNA polymerase III. The 37 above between 3 from BP 7SK RNA coding region there is a sequence promote transcription. RNA polymerase III promoter flanking sequences plasmid transcription, it can be the supervision shows that the internal promoter sequence is not required, a complete absence of 7SK RNA coding region. Transcription, to stretch feature the end of the T residues of RNA polymerase III transcription. Reduce the efficiency TATA, of significant transfer box, at position -25, organizer, has a mutation in it. Upstream sequence, enhance the efficiency of the organizer to -243 from position -37. Promoter recognized by RNA polymerase III is similar to the promoter of gene transcription by RNA polymerase II functionally also structural.

There are Argonaute family of at least three were found in eukaryotes. Subfamily is located in the sub-fission PIWI animals, plants, and yeast, found in only animals unlike before. The RasiRNA, it is observed in Drosophila, a unicellular eukaryotic cells Several different vertebrates, including mammals and invertebrates, and pills that are observed in many types, its presence in mammals has not been determined But, invertebrates and vertebrates, the bottom active rasiRNA is possible should be observed in other animals further to binding proteins are included. It contains a sub PIWI Argonaute protein was observed none, Schizosaccharomyces pombe, a yeast species, and is not observed in plants RasiRNAs. Mother and associated rasiRNA Pirna More specifically, it is connected to the mother and, therefore, it mother and related rasiRNA Pirna found to be a protein PIWI subfamily that conclusions have been derived.

RasiRNA distinguishes it from other RNAi pathway of Pirna and the like (Sirna) small interfering RNA micro RNA and such (the miRNA). In front of the Argonaute protein subfamily, through RasiRNA function, unlike the behavior of siRNA and peace by PIWI Argonaute protein subfamily. RasiRNA is different at that size. The piRNA, a length is 21-23 nucleotides, the siRNA, is miRNA, contrary to rasiRNAs, in response to biological length, and a length of 20 to 25 nucleotides is 24-31 nucleotides, origin length is 24-29 nucleotides. SiRNA obtained from both sense and antisense strands are different, rasiRNA was received by the antisense. Require dicer -1 for the production, Dicer -2 while the need siRNA, Interestingly,, miRNA of is required one of the rasiRNA, but generates a miRNA of DCL1 24 base in some plants siRNA to generate a 24 nucleotide while DCL2 If you do not have the protein Dicer similar have been identified in (DCL). This study shows the rasiRNA production not just of the siRNA and non-peace, between rasiRNA no PIWI protein, can be found in plants.

In addition, I assumed that the RNA rasiRNA source was generated by annealing of transposable elements and related antisense double sense have been left behind. It has nothing to do with Dicer in the biosynthesis of rasiRNA, but require, the eggplant and 3, PIWI Argonaute protein Argo is a PIWI-like protein. RasiRNA biosynthesis mechanism is ping-pong mechanism. RNA rasiRNA to PIWI / AUB related. I is compatible with (name rasiRNA hence) antisense strand of repetitive sequence elements and retrotransposons in rasiRNAs. I was prepared from the sense strand RNA associated with AGO3. ping-pong mechanism can be seen in this image of the end is still unknown, is a mechanism for ‘while forming the, end of rasiRNA’ 3 to generate 5.

To siRNA action mRNA cleavage in order to regulate the transcriptional silencing and chromatin structure while miRNA act in mRNA cleavage and translational repression, of rasiRNA act. In Drosophila, the mutation of the protein PIWI that binds to rasiRNA lead to loss of germ cells and infertility in men and women. And make clear that it is an object of the rasiRNA time, suppression of transposon is not affected by the loss of Dicer in germ cells. In a similar manner to that of siRNA and peace, road siren is evolutionarily conserved, it is dependent on the homology. If rasiRNA path is not available, germ cells can be subjected to retrotransposition that are reflected as DNA damage and signal the cells to apoptosis. RasiRNA is the key control mechanism of many organisms as part of the RNA interference pathway.

Plant miRNA may be coupled their goals in both the untranslated region and the coding region. In contrast to the miRNA Animal shows a partially complementary to the mRNA target only those in general. The region “seed 6-8 nucleotides is. Combinatorial regulation is considered an important factor for target specificity is a function of the adjustment of the miRNA is the length of the 5 ‘end of the miRNA Animal . it is possible to have a mRNA targets several different, also target the can,. miRNA being targeted by miRNA plurality was characterized in the early 1990s for the first time. Nevertheless, miRNA of the, miRNA is miRNA research., which is not recognized as a distinct class of regulatory biological with reservation function in the early 2000s, we show more than one role in the negative, blockade and degradation of (transcript, translational suppression rule if we may translational activation) and (transfer Joining possibility of regulation and positive), but affects gene regulation, miRNA expression in groups. variety that may be involved in the biological processes most The miRNA, it has been found in different types of cells, aberrant expression of. miRNA tissue is considered the treatment of miRNA-based and has been implicated in many disease states.

Before the publication of the discovery of those naming names of standard system, miRNA of verification is assigned experimentally. Prefix “peace” has continued and a number dash, the latter shows the sequence of naming often. The declared before, miR-123 is of, for example, of miR-456, it was discovered probably. The “meal” in the case of the, upper case, “meal” refers to the pre-miRNA refers to the mature form. MiRNA having a sequence substantially identical except for the nucleotides of one or two are annotated with minimal further. For example, Mir-123a is linked closely to the Mir-123b. Same as mature miRNA but preliminary miRNA leading to 100% and is arranged at different locations within the genome, is shown in dash extra suffix number. For example, two leads from the HSA-MIR-194, however, pre-miRNA is located in the different regions of the genome mature miRNA identical to the HSA-MIR-194-1 on (HSA-MIR-194). Species of origin is indicated by a prefix of three letters, for example, human HSA-MIR-123 is a (Homo sapiens) peace, sheep paddle-MIR-123 is the (sheep) Myrna. Prefix Other common, include “D” for the (study fly in genetic studies often fruit) for virus “V” (of miRNA encoded by the viral genome) peaceful and Drosophila have. When you derive from the opposite strand of the same pre-miRNA, they, two mature micro RNA is the suffix or-3P-5P labeled. (In the past, made this “S” difference ‘bottom’ and (sense) and (antisense)). After showing miRNA expression at low levels compared with the miRNA in the opposite side of the hairpin, the name when it is known asterisk relative levels of expression. For example, the hairpin of miR-123 * Sheapure and miRNA Mir -123, -123 peace will be found in the cell.

By genetic or their own micro RNA is produced by the intron. Video of this process can be found here. It is estimated for the antisense gene orientation adjacent or are intergenic, the majority of genes, wherein the miRNA and are transcribed as a single unit. However, in some cases, providing an average value of the protein-coding gene and adjustment of the miRNA that is transferred with the host gene micro RNA gene, it is coupled. 40% of miRNA gene may be located in exons of the transcripts encoding the long non-protein, or introns of a gene encoding a non-protein and protein. These are typically, but not exclusively, it is found in the sense orientation, and is adjusted with the genes of the host normally. The other genes, this does not mean that would be homologous to the structure and function mature miRNA family necessarily, but the promoter of miRNA the whole, polycistronic die having a line of discrete multiple be processed mature miRNA I show consists of 48% from 42 miRNA of all outgoing from. These promoters may have a similarity of pattern of the particular promoter gene transcription by other RNA polymerase II, such as a gene encoding such a protein is shown. The DNA template, there is no word at the end of the mature miRNA production: shows (IsomiRs) RNA editing, the site-specific modification of RNA sequences, 6% of the miRNA of human products, other than those encoded by the DNA were prepared. Range and diversity of action of miRNA will increase beyond the genome involved in it by this alone.

The several types of small RNA, have been proposed repressor of gene expression great potential for use in gene therapy. The (III of Pol) RNA polymerase III, little is located in the intracellular compartment of different intracellular small RNA expression products such as usual, RNA that is highly structured is ideal for some. We designed a cassette with the Pol III promoter of human cells for quality, high-level expression of the RNA of small nucleolus and nucleoplasm. Nuclear RNA small U6 (a snRNA), 5S ribosomal RNA (the rRNA), and destination intracellular and transcription levels were compared to express the transcription into components 7SL RNA of a signal recognition particle. RNA is a specific inhibitor, in this way, allowing these tapes can not necessarily predict the same input RNA in place in the cell some place the most effective. Small interfering RNA several insert (of siRNA) will be tested for efficacy. One of the inputs of the siRNA that reduces the expression of lamin when it is transcribed from the promoter of the U6 snRNA in the core when it is found in the nucleolus and cytoplasm and transfer of ink 5S rRNA’s and 7SL RNA-based It does not affect the expression of the laminate. In order to investigate the general nature of the driving U6 siRNA inhibition with siRNA targeting of HIV was further tested by co-transfection with provirus in cell culture. The degree of inhibition of HIV-1 varies between the insert, but the results, cassette U6 has been shown to allow expression of the siRNA-like inhibitors of HIV gene expression.

To the genomic DNA, and a gene of an organism, including leading to the production of specific proteins serve multiple functions specific to nucleic acid coding for protein synthesis. Transcription and translation: the fusion protein, two steps are included. Transcription creating extra copies of DNA sequences and RNA, translation is the subsequent processing used for the synthesis of RNA from the amino acids of the protein it really is. Production of proteins, inhibition of the transfer process, resulting in a blocking its function in the end. In order to understand the role better protein plays in a particular disease state, these compounds make a useful research tool, Sigma-Aldrich, offers a number of small molecules that inhibit protein translation.

RNA interference called (PTGS) post-transcriptional gene silencing (RNAi), typically by causing the destruction of mRNA specific molecules, RNA molecules are biological processes that inhibit gene expression. Historically, transcriptional gene silencing it is (PTGS) after co-suppression, it is known, such as suppression, the name of the other. Only after a thorough understanding of the process of apparently unrelated these, that they explained the phenomenon of RNAi all became clear it. 2006, Craig C. Mello and Andrew Fire, the publication is elegance in 1998 they shared the Nobel Prize in Physiology or Medicine for their work in RNA interference of nematode worm C,.

It is the center that the interfering RNA – two types of small ribonucleic acid (RNA) molecule – RNA and micro (the miRNA) small interfering RNA (the siRNA). The RNA, is a direct product of the gene, by preventing the mRNA from the protein production RNA and other specific, the (mRNA), for example, RNA small these, the molecules that increase or decrease its activity It can be coupled. Transposon and virus – not only plays an important role in protecting cells against parasitic nucleotide sequence, RNA interference, gene expression in general and to direct development.

The RNAi, located in eukaryotic organisms including many animals, the method, long double-stranded RNA enzyme dicer cutting (dsRNA) molecules into short fragments of 20 nucleotides difficult-dual, which is called siRNA of, It is initiated by the. In other words, each siRNA, has developed a direction and passenger strand of single-stranded 2 (SS) ssRNAs, you want to use. Passenger strand is reduced, the management direction contained RNA-induced silencing complex (RISC). Research results are post-transcriptional gene silencing that occurs when using a nucleotide sequence complementary to couple messenger RNA molecule chains and induce cleavage by catalytic component Argonaut, the RISC complex most. The restricted the molar concentration of siRNA Initially, in a particular organism, this process can spread throughout the body are known.

In cell culture, it is possible to induce suppression of specific genes of interest strongly selectively introducing synthetic dsRNA into cells, RNAi has become a valuable research tool for both in vivo. RNAi can be used for large screen to be canceled each gene to cells can be systematically and serve to identify the necessary components for event and cell specific processes, such as cell division. The road, it is used as a practical tool of medicine and biotechnology.

In eukaryotic cells, specific, and includes an enzyme having reverse transcriptase activity called telomerase. Telomerase is a reverse transcriptase which extends the ends of linear chromosomes. The synthesized “junk” DNA or DNA sequences that are repeated, telomerase RNA carry therefrom. This iterative sequence can be called a telomere DNA, is considered as a “cap” on chromosomes. Linear chromosomes since the duplicated each time, which is important, it is shortened. Not a repeat sequence is not essential for DNA sequence encoding a protein located at the ends of chromosomes, some of them, but ends of chromosomes, “hat” or “junk” DNA, the shortening is eliminated.

Often, without losing the DNA sequence cancer cells encode proteins important in order to be able to replicate their genome indefinitely, Telomerase is activated in cancer cells. Activation of telomerase may be part of a process that allows cancer cells become immortal. By using the remaining 10% of the alternate route is known as the alternate telomere elongation and maintenance ALT telomere, telomerase in recycling factor cancers indicates that occur in 90% of the carcinogenic all tumors in vivo by telomere elongation Because it is.

Found separated by Howard Temin at the University of Wisconsin-Madison in virion RSV, in David Baltimore independently, reverse transcriptase, was a 2 RNA tumor viruses at MIT in 1970 and R-MLV again RSV. So inconsistent with the central dogma of molecular biology said is transcribed into RNA, which is translated into protein DNA, the idea of ​​reverse transcription, it is very unpopular at first. However, in 1970, David Baltimore scientists and Howard Temin When is the possibility that the reverse transcription of both names independent reverse transcriptase, genetic information is allowed finally to be sent in this way I have found an enzyme involved. It is encoded by the viral reverse transcription using the enzymatic replication process, enzymes are used. Then, to use their genome the enzyme reverse transcriptase RNA in a DNA that is integrated into the host genome is replicated therewith, for example, reverse transcription of RNA viruses such as retroviruses. The reverse transcription, a DNA virus, such as hepadnaviruses such as, RNA can be used as a template for the assembly, and you can make the DNA strand. HIV-infected persons using this enzyme. It would not have been able to cause the failure to reproduce the Zu reverse transcription viral genome is incorporated into the host cell.

To create a double-stranded DNA and the transfer direction of transcription of the DNA product short initial RNA-dependent DNA synthesis to the acceptor template region at the other end of the genome that can be processed to reach by reverse transcriptase later The DNA-dependent DNA activity contains.  It is located at the 5 ‘end 3’ end of the retroviral RNA. Place called (PBS) primer binding sites are annealed primers viral RNA is called the leader of PBS FIG 5 ‘is referred to the end of RNA 3 end of the RNA to a site and, as a PBS U5’ have. It is developed with the double-stranded viral RNA primer tRNA is paired with form-based and PBS 22 and 14 nucleotides. Fact ‘reverse transcription Since DNA was synthesized from 3 that is located near the 5 PBS end of the primer in’ to 3 ‘(for RNA) 5 direction, by the end of the viral RNA, a rarity There is no ‘. Therefore, the position, the reverse transcriptase primer and achieves comprising (RN RNase H), and various enzymes DNA polymerase and several steps, ribonuclease H. Go to the 3 ‘end of the viral RNA, and it is required to develop a polynucleotide.  Reverse transcriptase of HIV have ribonuclease activity that degrades the viral RNA during the synthesis of DNA-dependent DNA polymerase and copy DNA with the sense DNA strand antisense DNA to form an intermediate double-stranded DNA virus (vDNA).

If you want to play in the life cycle of a retrovirus, and there are three different systems of the next. First, the present invention, reverse transcriptase to synthesize a complementary strand viral DNA and viral RNA, the DNA subsequently. The DNA polymerase of the host cell, when duplicating an integrated viral DNA, replication process of the second occurs. Finally, I can transcription of RNA polymerase II proviral DNA in RNA is packaged in virions. As a result, the mutation can occur in one or all duplicate one of these steps. Since then, that unlike the DNA polymerase of all the other does not have a high error rate on record at the time of the RNA correction capability, to DNA by reverse transcriptase. This high error rate can accumulate rapidly as compared with that mutation to examine the morphology of replication. In reverse transcriptase generation of commercially available, has been cited by the leadership as an error rate of up to 1 M-MLV 30,000 for base and base of 17,000 AMV from 1 by Promega. Also produce non-enzyme reverse transcription single nucleotide polymorphism, for example, to be involved in processes such as creating meaningless transcripts artificial transcription united and exon shuffling is shown. This reverse transcriptase that can be fully demonstrated in vivo, the switching operation of the template to be one reason for the discovery of transcripts without thousands annotate the genome of the model organism has been speculated was.

It is a mechanism in prokaryotes that causes the RNA transcription (referred not to Rho-dependent termination also) internal termination is stopped. In this mechanism, mRNA is cytosine – Includes an array can be calculated in a pair with itself to form a stem-loop structure 7-20 base pairs in length guanine base pair is rich. These bases, so to form three hydrogen bonds with each other, very strong. I have a chain of uracil residues after the stem-loop structure. Link between the uracil and adenine is very weak. Polymerase closely enough to bind to stem loop structure To be thrown down temporarily proteins associated with RNA polymerase (Nusa Dua). This break, poly – are consistent with transcription polymerase sequence of uracil. Uracil bonds – weak adenine can be dissociated to relax from the RNA polymerase, lowering the energy of the destabilization of the double-stranded RNA-DNA.

Will cause the RNA polymerase to stem-loop structure that do not comply by poly uracil sequence will pause, but so is stable too to fully relax to cause an end to the double, usually, it after a short time, I will continue to transcription.
In many cases, ρ-independent transcription termination mechanism is the basis of the activity of the RNA cis-acting regulatory elements, as riboswitch.

E. coli genome equencing whole may have a termination sites most of the operon is not dependent on the row are shown. In the transcribed RNA, a series of U residues in front of those of self-complementary region a GC-rich and nucleotides intervening some: I have two characteristics in extreme sequence of these. Area of ​​the self-growth of additional RNA strand are synthesized with each other to form a stem-loop structure, base pairs of additional sequences. The stem-loop structure is believed to interact with the recording of E. coli RNA polymerase and cause it to break. Further, base pairs between the residues in the template DNA strand U and Watson 3 ‘end of the residual nascent RNA chain – very unstable as compared to other types of Crick base pairs. These two features, have solved the release of the RNA strand of the transcription complex at the end sites that do not depend on Rho probably. Mutations that decrease and results dyad symmetry to U, a continuous low end to reduce the part of these sites.

Several mechanisms for the regulation of transcription is found in eukaryotes and bacteria. RNA polymerase plays a role of two primary mechanisms for the conclusion of the occurrence transcription in E. coli. Additional proteins, called rows, transcription terminators, a mechanism is required, but not the other. In many cases, these mechanisms are referred to as dependent end of Rho If you do not depend on low. In eukaryotes, the mechanism of transcription termination seems to be different in each RNA polymerase three. Here, I focus on the end of the first mechanism in bacteria that will be understood from the mechanisms of eukaryotic organisms has been described by way of example research well two of termination of transcription of eukaryotic more clearly.

Another mechanism for the regulation of gene expression in bacteria, called recognized by the analysis of a particular strain of E. coli mutant first tryptophan operon is attenuated. In the presence of tryptophan, tryptophan repressor, please recall that to inhibit the transcription of TRP operon. However, it is not exhaustive, according to protein synthesis, this inhibition is complemented by the weight loss to provide the level of regulation of tryptophan synthesis.

In essence, attenuation results in early termination of transcription at the attenuator site located downstream of the coding sequence of the enzyme TRP and before, from the operator region – promoter. The presence of E. coli, the tryptophan and mutant with a small deletion in the area of ​​manufacturing tryptophan operon more than the normal amount of tryptophan synthase in the absence. Trp mRNA of the Trp promoter nearby sequence comparison of researchers at the start of the RNA molecule, deletions and these, or may lead to increased synthesis of DNA region of Trp in both mutant and normal E. mRNA molecules of normal, contains 162 nucleotides upstream of Trp August the first initiation codon of the enzyme that is encoded TRP-five in order to understand. This part of the mRNA are referred to as (L) leader sequence. MRNA transcript tryptophan rich TRP only and will not be transferred consists of the rest of the 7 KB TRP operon ≈ and only leader RNA by virtue of the action of the tryptophan repressor of E. coli cells normal production the transcription of these. When tryptophan is limited, however, comprises a coding sequence for all of the enzyme is encoded trp promoter and leader sequence, tryptophan operon is transferred as a whole. normal cells than do mutant cells is the attenuation region has been deleted, to produce a mRNA of Trp twist in all conditions.