IDENTIFICATION OF SUMO-2/3 MODIFIED PROTEINS ASSOCIATED WITH MITOTIC CHROMOSOMES

ABSTRACT: Sumoylation is essential for progression through mitosis, but the specific protein targets and functions remain poorly understood. In this study, we used chromosome spreads to more precisely define the localization of SUMO-2/3 to the inner-centromere and protein scaffold of mitotic chromosomes. We also developed methods to immune-purify proteins modified by endogenous, untagged SUMO-2/3 from mitotic chromosomes. Using these methods we identified 149 chromosome associated SUMO-2/3 substrates by nLC-ESI-MS/MS. Approximately one-third of the identified proteins have reported functions in mitosis. Consistent with SUMO-2/3 immunolocalization, we identified known centromere and kinetochore associated proteins, as well as chromosome scaffold associated proteins. Notably, >30 proteins involved in chromatin modification or remodeling were identified. Our results provide insights into the roles of sumoylation as a regulator of chromatin structure and other diverse processes in mitosis. Furthermore, our purification and fractionation methodologies represent an important compliment to existing approaches to identify sumoylated proteins using exogenously expressed and tagged SUMOs.

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Homo Sapiens (ncbitaxon:9606)

SUBMITTER: Michael Matunis 

PROVIDER: MSV000078890 | MassIVE | Tue Oct 07 09:24:00 BST 2014

SECONDARY ACCESSION(S): PXD001534

REPOSITORIES: MassIVE