CSG2 (YBR036C) notes

UniProt P35206, 10-TM ER membrane protein; regulatory subunit of the IPC mannosyltransferase (MIPC synthase) complexes Sur1(Csg1)-Csg2 and Csh1-Csg2; ER Ca2+ release channel [UniProt:P35206].

• MIPC synthesis: PMID:12954640; PMID:12954640. Catalytic activity resides in Sur1/Csg1 and Csh1, not Csg2.
• Ca2+ sensitivity of csg2/cls2 mutants; ER membrane by IF PMID:7854312. Ca2+ sensitivity due to IPC accumulation; suppressed by sphingolipid synthesis mutants PMID:8063782.
• ER Ca2+ release channel (bilayer currents), needed for starvation-induced autophagy PMID:37349354.

Pathway context

• YeastPathways attaches CSG2 to IPC + GDP-mannose -> MIPC (EC 2.4.1.-). Csg2 is a non-catalytic regulatory subunit of the MIPC synthase; the transferase is Sur1/Csh1. Appropriate as complex member, not as the catalyst.