Negative Stranded RNA Viruses

Negative-stranded RNA viruses include those viruses with a single-stranded RNA genome that is the opposite sense, or complementary, to that of mRNA, and hence is not decoded directly by translation. Following infection, the viral genome of negative-stranded ssRNA viruses is transcribed by a virion-associated viral RNA-dependent RNA polymerase to produce mRNA for translation, and then replicated to produce full-length positive (and subsequently negative) sense ssRNA. Among the negative-stranded...

Systematic Surveys for MiRNA Editing Sites

A-to-I editing of a pri-miRNA was first reported in 2004 (Luciano et al. 2004). PCR amplification and sequencing of the region surrounding the pri-miR-22 hairpin revealed editing at several positions in mouse brain and human brain, lung, and testis (Fig. 2a). However, editing frequency was very low less than 10 . While the biological consequence of this editing is still unclear, its discovery demonstrated the existence of miRNA editing and sparked further studies. In 2006, Blow et al. attempted...

References

Athanasiadis A, Rich A, Maas S (2004) Widespread A-to-I RNA editing of Alu-containing mRNAs in the human transcriptome. PLoS Biol 2 e391 Barak M, Levanon EY, Eisenberg E, Paz N, Rechavi G, Church GM, Mehr R (2009) Evidence for large diversity in the human transcriptome created by Alu RNA editing. Nucleic Acids Res 37 6905-6915 Bartel DP (2004) MicroRNAs genomics, biogenesis, mechanism, and function. Cell 116 281-297 Bass BL (2002) RNA editing by adenosine deaminases that act on RNA. Annu Rev...

Adar2 Rlkenvqfhlyistspcgdarif Adar1 Qikktvsfhlyistapcgdgalf

Fig. 10 Amino acid sequence alignment of ADAR1 and ADAR2. Conserved residues are marked in green, position 455 of ADAR2 and the equivalent position in ADAR1 are marked in This indicates that R455, while it may be proximal to the adenosine ring during the reaction, is not required for efficient catalysis. The relatively high reactivity of the ADAR2 R455A mutant allowed us to compare the reactivity of several nucleoside analogues placed at the editing site (discussed in detail below). These...

Effect on Mature MiRNA Function

Following loading onto RISC, the miRNA guides RISC to sequester or degrade its complementary mRNAs (Kim et al. 2009 Krol et al. 2010 Siomi and Siomi 2010). Edited miRNAs can also be loaded onto RISC if editing did not prevent their maturation. Since editing alters the base pairing properties of the miRNA, it can also redirect its silencing. This is especially the case when editing takes place within the seed sequence, or nucleotides 2-8, of the miRNA, which is particularly important for target...

Hepatitis Delta Virus

Hepatitis delta virus (HDV) is an important human pathogen that causes potentially severe acute and chronic hepatitis. It requires simultaneous infection with hepatitis B virus (HBV). The helper function provided by HBV is the envelope protein, HBsAg, which is required for the assembly and release of HDV particles, as well as the ability of these particles to attach to and infect hepatocytes, the primary targets of infection. Compared with those infected with HBV alone, individuals infected...