The yeast SUMO isopeptidase Smt4/Ulp2 and the polo kinase Cdc5 act in an opposing fashion to regulate sumoylation in mitosis and cohesion at centromeres

Summary: Chromosome segregation during cell division is controlled and adapted by kinetochores, which connect spindle microtubules to chromosomal centromeres. A mechanism that regulates kinetochore sumoylation has been identified, with a conserved surface of the Ctf3/CENP-I kinetochore protein providing a binding site for the SUMO chain-removing enzyme Ulp2. Disabling Ulp2 recruitment to kinetochores leads to defective chromosome segregation due to elevated sumoylation levels.

Summary: The development of the brain requires a dynamic balance of SUMOylation/deSUMOylation to control neuronal polarization and migration, with the impact of Drp1 on mitochondrial morphology and endoplasmic reticulum controlled by Senp5L/5S competitively.

Summary: SUMO chains target SMC complexes and are prevented from turnover by the SUMO protease Ulp2. The essential role of Pds5 is to counteract SUMO chains with Ulp2. Timing the assembly of SUMO chains on chromosomes helps regulate the availability of SMC complexes.

Summary: In this study, it was elucidated that the poly-SUMO-2/3 chain modification of Nuf2 is significantly upregulated during mitosis, facilitating the kinetochore localization of CENP-E and chromosome congression. The results also showed that expressing fusion proteins between Nuf2 and SUMO-conjugating enzyme Ubc9, or three SUMO-2 moieties, can rescue the mitotic defects caused by global inhibition of sumoylation, highlighting the importance of poly-SUMO-2/3 chain modification in regulating mitotic processes.

Summary: RepoMan, a regulatory subunit of protein phosphatase 1 (PP1), is transiently modified with SUMO-2 during late telophase, which enhances its binding affinity with lamin A and contributes to the recruitment and dephosphorylation of lamin A. Transient SUMOylation of RepoMan plays a crucial role in the spatiotemporal regulation of lamin A dephosphorylation and subsequent nuclear lamina formation at the end of mitosis.