PolyADP-ribosylation

SET8 is post-translationally poly ADPribosylated by PARP1 on several lysine residues, leading to SET8 degradation via ubiquitylation and genome-wide aberrant H4K20 methylation.

Structural insights into the poly-ADP-ribosyltransferase tankyrase reveal its filamentous architecture and illustrate how assembly controls catalytic and non-catalytic functions.

Poly-ADP-ribosylation (PARylation) is a well-known posttranslational modification of proteins. Here the authors show that beyond proteins also mammalian single-stranded DNA is PARylated in vitro and in vivo.

Deubiquitinases (DUBs) remove ubiquitin from its target proteins. Here, authors compare the regulatory effects of the proteasome and DUBs on the ubiquitinated proteome. They find preferential sets of substrates regulated by DUBs or by the proteasome. Moreover, they find that PARP1 is hyper-ubiquitinated in response to DUB inhibition, which increases its enzymatic activity.

Fu, et al. report that PARP1-dependent poly(ADP-ribsoyl)ation of the P-TEFb subunit CycT1 suppresses its phase separation, which prevents its interaction partner CDK9 from hyperphosphorylating RNA polymerase II and thereby blocks transcription.