CLSY docking to Pol IV requires a conserved domain critical for small RNA biogenesis and transposon silencing.

Eukaryotes must balance the need for gene transcription by RNA polymerase II (Pol II) against the danger of mutations caused by transposable element (TE) proliferation. In plants, these gene expression and TE silencing activities are divided between different RNA polymerases. Specifically, RNA polymerase IV (Pol IV), which evolved from Pol II, transcribes TEs to generate small interfering RNAs (siRNAs) that guide DNA methylation and block TE transcription by Pol II.

DEAD box RNA helicase 5 is a new pro-viral host factor for Sindbis virus infection.

Background: RNA helicases are emerging as key factors regulating host-virus interactions. The DEAD-box ATP-dependent RNA helicase DDX5, which plays an important role in many aspects of cellular RNA biology, was also found to either promote or inhibit viral replication upon infection with several RNA viruses. Here, our aim is to examine the impact of DDX5 on Sindbis virus (SINV) infection.

Peptide-Based Covalent Inhibitors Bearing Mild Electrophiles to Target a Conserved His Residue of the Bacterial Sliding Clamp.

Peptide-based covalent inhibitors targeted to nucleophilic protein residues have recently emerged as new modalities to target protein-protein interactions (PPIs) as they may provide some benefits over more classic competitive inhibitors. Covalent inhibitors are generally targeted to cysteine, the most intrinsically reactive amino acid residue, and to lysine, which is more abundant at the surface of proteins but much less frequently to histidine. Herein, we report the structure-guided design of targeted covalent inhibitors (TCIs) able to bind covalently and selectively to the bacterial sliding clamp (SC), by reacting with a well-conserved histidine residue located on the edge of the peptide-binding pocket.

Heat stress promotes Arabidopsis AGO1 phase separation and association with stress granule components.

In , ARGONAUTE1 (AGO1) plays a central role in microRNA (miRNA) and small interfering RNA (siRNA)-mediated silencing. AGO1 associates to the rough endoplasmic reticulum to conduct miRNA-mediated translational repression, mRNA cleavage, and biogenesis of phased siRNAs. Here, we show that a 37°C heat stress (HS) promotes AGO1 protein accumulation in cytosolic condensates where it colocalizes with components of siRNA bodies and of stress granules.

CLSY docking to Pol IV requires a conserved domain critical for small RNA biogenesis and transposon silencing.

Eukaryotes must balance the need for gene transcription by RNA polymerase II (Pol II) against the danger of mutations caused by transposable element (TE) proliferation. In plants, these gene expression and TE silencing activities are divided between different RNA polymerases. Specifically, RNA polymerase IV (Pol IV), which evolved from Pol II, transcribes TEs to generate small interfering RNAs (siRNAs) that guide DNA methylation and block TE transcription by Pol II.