Carboxyl-terminal Tail-mediated Homodimerizations of Sphingomyelin Synthases Are Responsible for Efficient Export from the Endoplasmic Reticulum.

ABSTRACT: Sphingomyelin synthase (SMS) is the key enzyme for cross-talk between bioactive sphingolipids and glycerolipids. In mammals, SMS consists of two isoforms: SMS1 is localized in the Golgi apparatus, whereas SMS2 is localized in both the Golgi and plasma membranes. SMS2 seems to exert cellular functions through protein-protein interactions; however, the existence and functions of quaternary structures of SMS1 and SMS2 remain unclear. Here we demonstrate that both SMS1 and SMS2 form homodimers. The SMSs have six membrane-spanning domains, and the N and C termini of both proteins face the cytosolic side of the Golgi apparatus. Chemical cross-linking and bimolecular fluorescence complementation revealed that the N- and/or C-terminal tails of the SMSs were in close proximity to those of the other

SUBMITTER: Hayashi Y 

PROVIDER: S-EPMC5247646 | biostudies-literature | 2017 Jan

REPOSITORIES: biostudies-literature