Abstract 1318: Mps1 is modified by sumoylation during the cell cycle

Abstract

Abstract Mps1 is a dual specificity protein kinase with crucial roles in regulating the spindle assembly checkpoint and chromosome microtubule attachment. Molecular mechanisms that regulate Mps1 levels and its activity during mitosis remain unclear. Given that sumoylation plays an important role in mitotic progression, we investigated if Mps1 could be modified by SUMO conjugation. Endogenous sumoylated Mps1 was detected by nickel affinity pull-down from HeLa cells that constitutively expressed His6-SUMO1 or His6-SUMO2. When HEK293T cells transfected with a plasmid construct expressing Myc-Mps1, along with plasmids expressing His-SUMO-1 and FLAG-UBC9, were analyzed sumoylated Mps1 was also detected in both asynchronized and mitotic cell populations. Expression of wild-type FLAG-SENP1 completely abrogated sumoylated Mps1 compared with cells transfected with enzymatically defective FLAG-SENP1, confirming that Mps1 is modified by sumoylation. We also identified potential lysine residues of Mps1 that were sumoylated by the mutagenesis approach. Our study reveals that Mps1 is modified via sumoylation and that future experiments will be centered on understanding the biological function of this modification during the cell cycle. Citation Format: Agnese Restuccia, Feikun Yang, Yao Yixin, Wei Dai. Mps1 is modified by sumoylation during the cell cycle. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1318. doi:10.1158/1538-7445.AM2014-1318