Biology subjects

Wozniak, R. W.

Publications and source records attributed to Wozniak, R. W..

3 recordsLinked to original sources

bioRxiv2021

Phosphorylation-dependent mitotic SUMOylation drives nuclear envelope-chromatin interactions

In eukaryotes, chromatin binding to the inner nuclear membrane (INM) and nuclear pore complexes (NPCs) contributes to spatial organization of the genome and epigenetic programs important for gene expression. In mitosis, chromatin-nuclear envelope (NE) interactions are lost and then formed again as sister chromosomes segregate to post-mitotic nuclei. Investigating these processes in S. cerevisiae, we identified temporally and spatially controlled phosphorylation-dependent SUMOylation events that positively regulate post-metaphase chromatin association with the NE. Our work establishes a phosphorylation-mediated targeting mechanism of the SUMO ligase Siz2 to the INM during anaphase, where Siz2 binds to and SUMOylates the VAP protein Scs2. The recruitment of Siz2 through Scs2 is further responsible for a wave of SUMOylation along the INM that supports the assembly and anchorage of subtelomeric chromatin at the INM and localization of an active gene (INO1) to NPCs during the later stages of mitosis and into G1-phase.

cell biology↗

bioRxiv2020

Nodosome inhibition as a novel broad-spectrum antiviral strategy against arboviruses and SARS-CoV-2

In the present report, we describe two small molecules with broad-spectrum antiviral activity. These drugs block formation of the nodosome. The studies were prompted by the observation that infection of human fetal brain cells with Zika virus (ZIKV) induces expression of nucleotide-binding oligomerization domain-containing protein 2 (NOD2), a host factor that was found to promote ZIKV replication and spread. A drug that targets NOD2 was shown to have potent broad-spectrum antiviral activity against other flaviviruses, alphaviruses and SARS-CoV-2, the causative agent of COVID-19. Another drug that inhibits the receptor-interacting serine/threonine-protein kinase 2 (RIPK2) which functions downstream of NOD2, also decreased replication of these pathogenic RNA viruses. The broad-spectrum action of nodosome targeting drugs is mediated, at least in part, by enhancement of the interferon response. Together, these results suggest that further preclinical investigation of nodosome inhibitors as potential broad-spectrum antivirals is warranted.

microbiology↗

bioRxiv2019

Passive diffusion through nuclear pore complexes regulates levels of the yeast SAGA and SLIK coactivators complexes

Nuclear pore complexes (NPCs) control gene expression by regulating the bi-directional exchange of proteins and RNAs between nuclear and cytoplasmic compartments, including access of transcriptional regulators to the nucleoplasm. Here we show that the yeast nucleoporin Nup170, in addition to binding and silencing subtelomeric genes, supports transcription of genes regulated by the SAGA transcriptional activator. Specifically, we show that less SAGA complex is bound to target genes in the absence Nup170. Consistent with this observation, levels of the SAGA complex are decreased in cells lacking Nup170, while SAGA-related SLIK complexes are increased. This change in the ratio of SAGA to SLIK complexes is due to increased nuclear activity of Pep4, a protease responsible for production of the SLIK complex. Further analyses of various nucleoporin mutants revealed that the increased nuclear entry of Pep4 observed in the nup170{Delta} mutant likely occurs as consequence of an increase in the sieving limits of the NPC diffusion channel. On the basis of these results, we propose that changes in passive diffusion rates represents a mechanism for regulating SAGA/SLIK complex-mediated transcriptional events.

cell biology↗