Identification of Phosphorylation Sites in the C-Terminal Region of Charged Multivesicular Body Protein 1A (CHMP1A)

Abstract

Human charged multivesicular body protein 1A (CHMP1A) displayed two bands on SDS–PAGE and differences in efficiency of complex formation with IST1. By site-directed mutagenesis and phosphate-affinity PAGE, we identified Ser¹⁷⁹ and Ser¹⁸² located in the C-terminal region as major phosphorylation sites that cause a mobility shift, but interaction with IST1 was not affected by Ser-to-Ala mutations.