Obraz biskupa v románskej dobe (pol. 11. – pol. 13. storočia)

Pol V Transcribes to Silence

In most cases, the functions of long noncoding RNAs remain uncertain. Working in the model plant Arabidopsis, Wierzbicki et al. (2008) provide evidence that transcription of intergenic noncoding regions by RNA polymerase V promotes heterochromatin formation and silencing of nearby genes.

All three SOS-inducible DNA polymerases (Pol II, Pol IV and Pol V) are involved in induced mutagenesis.

Most organisms contain several members of a recently discovered class of DNA polymerases (umuC/dinB superfamily) potentially involved in replication of damaged DNA. In Escherichia coli, only Pol V (umuDC) was known to be essential for base substitution mutagenesis induced by UV light or abasic sites. Here we show that, depending upon the nature of the DNA damage and its sequence context, the tw...

A transcription fork model for Pol IV and Pol V-dependent RNA-directed DNA methylation.

In Arabidopsis thaliana, nuclear multisubunit RNA polymerase IV (Pol IV) and RNA-DEPENDENT RNA POLYMERASE 2 (RDR2) are required for the biogenesis of 24-nucleotide small interfering RNAs (siRNAs) that direct DNA methylation and transcriptional silencing at target loci transcribed by nuclear multisubunit RNA polymerase V (Pol V). Pol IV and RDR2 physically associate and RDR2's polymerase activit...

RNA-Silencing Enzymes Pol IV and Pol V in Maize: More than one Flavor?

There are some puzzling genetic phenomena in nature that have kept geneticists busily searching for clues for decades. Among genetics’ X-files are cases in which alleles of the same gene have the same sequence but very different functional states. Gene behaviors of this sort fall under the heading of ‘‘epigenetic phenomena.’’ Traits attributable to epigenetically altered alleles (epialleles) ar...

Pol Arch Med Wewn becomes Pol Arch Intern Med.