Fbxw7β, E3 ubiquitin ligase, negative regulation of primary myoblast differentiation, proliferation and migration

Satellite cells attached to skeletal muscle fibers play a crucial role in skeletal muscle regeneration. During regeneration, the satellite cells proliferate, migrate to the damaged region, and fuse to each other. Although it is important to determine the cellular mechanisms controlling myoblast behavior, their regulators are not well understood. In this study, we evaluated the roles of Fbxw7 in primary myoblasts and determined its potential as a therapeutic target for muscle disease. We originally found that Fbxw7 beta, one of the E3 ubiquitin ligase Fbxw7 subtypes, negatively regulates differentiation, proliferation and migration of myoblasts and satellite cells on muscle fiber. However, these phenomena were not observed in myoblasts expressing a dominant-negative, F-box deleted Fbxw7 beta, mutant. Our results suggest that myoblast differentiation potential and muscle regeneration can be regulated by Fbxw7 beta.This research was supported by Basic Science Research Program (No. 2013R1A1A2009473 to HK) through the National Research Foundation of Korea funded by MISP and No. 2012M2A2A7010422 from the Nuclear Research & Development Program of the National Research Foundation grant (to SH) and No. 2014R1A1A1002599 from Basic Science Research Program (to JJ) through the National Research Foundation of Korea funded by MISP