Volume 27 Issue 4, April 2020

The scientific community is facing challenges due to the pandemic, and we pledge our support.

Adenosine deaminases acting on RNA (ADARs) catalyze deamination of adenosine to inosine. irCLASH identifies dsRNA substrates of ADARs and defines new features of their RNA-binding and editing activity, improving our understanding of these enzymes and aiding with future therapeutic applications.

Poly-(ADP-ribosylation) is a post-translational modification with broad roles in cell signaling. A recently reported crystal structure reveals how the accessory factor HPF1 extends the catalytic active site of PARP1 and PARP2 to promote the specific ADP-ribosylation of serine residues, a prerequisite for dynamic chromatin changes induced by DNA damage.

Emerging evidence that telomere-specific Shelterin components also play roles in DNA replication timing within heterochromatin and genome maintenance suggests a potential common evolutionary origin of their protective and regulatory functions.

The structure of the second zinc finger of SALL4 in complex with pomalidomide, cereblon and DDB1 reveals the unique details of SALL4 recruitment, providing insights for rational design of cereblon-binding drugs with reduced teratogenic risk.

Identification of SDD1 mRNA from Saccharomyces cerevisiae as an endogenous RQC substrate allows analysis of the mechanism underlying translational stalling and Hel2-dependent polyubiquitination of collided ribosomes to provide insight into ribosome dissociation.

A combination of cellular, in vitro phase separation and functional assays shows that the intrinsically disordered regions and bromodomains of the BRD4 short isoform induce formation of liquid-like condensates in cancer cell nuclei and enhance transcriptional activity.

Circular nanoparticles self-assembled from designed tandem repeat proteins are functionalized by fusing different protein domains at defined positions and copy numbers. These constructs can activate T cells via high-avidity interactions on the cell surface.

Transcriptome-wide mapping of RNAs bound by human ADARs reveals features that determine ADAR binding affinity and editing efficiency.

The chaperone Hsp27 prevents FUS from undergoing liquid–liquid phase separation until stress-induced phosphorylation causes Hsp27 to partition with FUS to preserve the liquid phase against amyloid fibril formation.

Cryo-EM structures of plasma membrane ATP release channel pannexin 1 reveal heptameric architecture, wide pore and a constriction potentially restricting the size of permeable substrates. Combined with functional assays, they offer insights into channel gating.

Cryo-EM structures of the bovine bestrophin-2 (Best2) channel, in the presence and absence of Ca²⁺, reveal the differences between bestrophin paralogs, the structural basis for the ion selectivity of bovine Best2 and its Ca²⁺-independent activity for Cl⁻.

Cryo-EM structures of human ESCRT-III proteins forming membrane-bound and membrane-free filaments show how CHMP1B and IST1 polymerize sequentially, driving membrane tubulation, constriction and bilayer thinning, leading to membrane fission.