PARP enzymes are increasingly taking on important roles beyond DNA repair. Huang et al. (2020b) report how the NAD+-dependent ADP-ribosylation of histone H2B by PARP-1 in complex with a metabolic enzyme suppresses the phosphorylation of an adjacent residue, impacting adipogenesis.

In this issue of Molecular Cell, Jalihal et al. (2020) show that cell volume changes upon osmotic stress result in rapid and reversible condensation of numerous multivalent proteins.

Recent work by Kadosh et al. (2020) suggests that mutant p53 activity in gut epithelia is influenced by local production of microbial metabolites. The switch of p53 from tumor suppressor to oncogene is location-dependent and is impacted by microbially derived gallic acid.

Nucleosomes package genomic DNA into chromatin. By regulating DNA access for transcription, replication, DNA repair, and epigenetic modification, chromatin forms the nexus of most nuclear processes. In addition, dynamic organization of chromatin underlies both regulation of gene expression and evolution of chromosomes into individualized sister objects, which can segregate cleanly to different daughter

The Cdk-Rb-E2F pathway integrates external and internal signals to control progression at the G1/S transition of the mammalian cell cycle. Alterations in this pathway are found in most human cancers, and specific cyclin-dependent kinase Cdk4/6 inhibitors are approved or in clinical trials for the treatment of diverse cancers. In the long-standing paradigm for G1/S control, Cdks inactivate the retinoblastoma

Jin et al. (2020) engineered new variants of CRISPR base editors that make precise genomic edits in rice protoplasts while minimizing untargeted mutagenesis.

In this issue of Molecular Cell, Benslimane et al. (2020) perform a CRISPR-Cas9 chemogenomic screen, identifying a network of DNA replication and genome integrity genes with the nutraceutical compound Resveratrol and its analog Pterostilbene, linking these compounds to the induction of DNA replication stress in mammalian cells.

The collaborative work of two HHMI groups, one at the University of Washington and the other at the Broad Institute of MIT and Harvard, led to the development of a novel molecular tool to edit single bases in the mtDNA (Mok et al., 2020).

Cell division requires the assembly and organization of a microtubule spindle for the proper separation of chromosomes in mitosis and meiosis. Phase separation is an emerging paradigm for understanding spatial and temporal regulation of a variety of cellular processes, including cell division. Phase-separated condensates have been recently discovered at many structures during cell division as a possible

Wagner et al. (2020), Bohlen et al. (2020), and Lin et al. (2020) use Sel-TCP-seq or selective ribosome profiling to gain insights into mRNA translation initiation, highlighting distinctions between yeast and higher eukaryotes and a role for eIF3 in elongation.

In this issue of Molecular Cell, Meydan and Guydosh present an elegant and rigorous addition to the exciting investigation of the roles played by ribosome collisions in eukaryotic translation and cellular homeostasis.

Klein et al. (2020) demonstrate for the first time that small-molecule cancer therapeutics are selectively partitioned and concentrated within phase-separated nuclear condensates, providing new insights to drug efficacy and creating the opportunity for enhanced control of therapeutic targeting.

Cancer immunotherapies enhance anti-tumor immune responses using checkpoint inhibitors, such as PD-1 or PD-L1 inhibitors. Recent studies, however, have extended the scope of immunotherapeutics by unveiling DNA damage-induced innate immunity as a novel target for cancer treatment. Elucidating the interplay among the DNA damage response (DDR), cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING)