PDS5

PDS5 refers to a family of eukaryotic proteins that regulate sister chromatid cohesion, a process essential for accurate chromosome segregation during cell division. The name derives from Pds5, a cohesin-associated protein first described in budding yeast. In vertebrates, two paralogs, PDS5A and PDS5B, have been identified.

PDS5 proteins are nuclear, chromatin-associated, large coiled-coil proteins that interact with the cohesin complex. They associate with core cohesin subunits such as SMC1/3 and the kleisin subunit (Scc1/RAD21) and with SA/STAG. The proteins are conserved across eukaryotes and often contain HEAT-like repeats that mediate protein-protein interactions.

Functionally, PDS5 supports establishment and maintenance of sister chromatid cohesion. It helps stabilize cohesin on chromatin and participates in the regulation of cohesin release during the cell cycle. In higher eukaryotes, PDS5 works within regulatory networks with WAPL and sororin to balance cohesin retention and release; in yeast, Pds5 also interacts with Eco1-mediated Smc3 acetylation to promote cohesion.

PDS5 is broadly conserved across eukaryotes and is essential for proper chromosome segregation. Genetic disruption often leads to defects in cohesion, chromosome mis-segregation, and cell cycle arrest or lethality in model organisms. Research on PDS5 continues to elucidate its precise regulatory roles in different organisms.