Premium
Identification of SUMO‐2/3‐modified proteins associated with mitotic chromosomes
Author(s) -
CubeñasPotts Caelin,
Srikumar Tharan,
Lee Christine,
Osula Omoruyi,
Subramonian Divya,
Zhang XiangDong,
Cotter Robert J.,
Raught Brian,
Matunis Michael J.
Publication year - 2015
Publication title -
proteomics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.26
H-Index - 167
eISSN - 1615-9861
pISSN - 1615-9853
DOI - 10.1002/pmic.201400400
Subject(s) - mitosis , sumo protein , chromatin , biology , centromere , microbiology and biotechnology , premature chromosome condensation , chromosome segregation , kinetochore , scaffold protein , chromosome , prophase , genetics , ubiquitin , dna , gene , signal transduction , meiosis
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 (small ubiquitin‐related modifier) to the inner centromere and protein scaffold of mitotic chromosomes. We also developed methods to immunopurify 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.