ST3 beta-galactoside alpha-2,3-sialyltransferase 5 (ST3GAL5)

Abstract

ST3Gal5 (GM3 synthase) was identified as the primary sialyltransferase responsible for the biosynthesis of ganglio-series gangliosides (Ishii et al. 1998; Kono et al. 1998; Fukumoto et al. 1999; Kapitonov et al. 1999). Ganglioside GM3 serves as a common precursor for complex gangliosides such as the a- and b-series gangliosides (Fig. 61.1). In addition, it was recently demonstrated that ST3Gal5 catalyzes GM4 synthesis in vivo (Chisada et al. 2009). Gangliosides are believed to form membrane microdomains (lipid rafts) that, with cholesterol and sphingomyelin, function as platforms for effective signal transduction in the plasma membrane (Simons and Gerl 2010) and participate in the regulation of numerous cellular processes, such as proliferation, differentiation, and adhesion (Hakomori 2004).