PRMT5 mediates FoxO1 methylation and subcellular localization to regulate lipophagy in myogenic progenitors
Kun Ho Kim, Stephanie N. Oprescu, Madigan M. Snyder, Aran Kim, Zhihao Jia, Feng Yue, Shihuan Kuang
Abstract
Development is regulated by various factors, including protein methylation status. While PRMT5 is well known for its roles in oncogenesis by mediating symmetric di-methylation of arginine, its role in normal development remains elusive. Using Myod1 Cre to drive Prmt5 knockout in embryonic myoblasts ( Prmt5 MKO ), we dissected the role of PRMT5 in myogenesis. The Prmt5 MKO mice are born normally but exhibit progressive muscle atrophy and premature death. Prmt5 MKO inhibits proliferation and promotes premature differentiation of embryonic myoblasts, reducing the number and regenerative function of satellite cells in postnatal mice. Mechanistically, PRMT5 methylates and destabilizes FoxO1. Prmt5 MKO increases the total FoxO1 level and promotes its cytoplasmic accumulation, leading to activation of autophagy and depletion of lipid droplets (LDs). Systemic inhibition of autophagy in Prmt5 MKO mice restores LDs in myoblasts and moderately improves muscle regeneration. Together, PRMT5 is essential for muscle development and regeneration at least partially through mediating FoxO1 methylation and LD turnover.