GOSR1

GOSR1, or Golgi SNAP receptor complex member 1, is a membrane-associated protein of the Golgi apparatus. It is commonly referred to as membrin and is a component of the cellular SNARE machinery that mediates vesicle fusion within the secretory pathway.

Functionally, GOSR1 participates in ER-to-Golgi transport by forming a SNARE complex that drives the fusion of cargo-laden vesicles with the Golgi membranes. In mammalian cells, membrin forms part of a cis-Golgi SNARE complex, typically partnering with other SNARE proteins such as syntaxin 5 (STX5), BET1-like protein 1 (BET1L), and SEC22B. Through these interactions, GOSR1 supports the proper trafficking, processing, and sorting of proteins and contributes to maintaining Golgi structure and function.

Expression of GOSR1 is broad, reflecting its fundamental role in the secretory pathway across various tissues. Its activity is important for the maturation and modification of secreted and membrane proteins, and disruptions can lead to broader defects in protein glycosylation and trafficking.

Clinical significance related to GOSR1 is an area of ongoing research. Rare variants or dysregulation of GOSR1 may contribute to diseases associated with impaired intracellular trafficking and glycosylation, though detailed genotype–phenotype relationships are not fully established. In model systems, loss of Gosr1 function often results in severe developmental abnormalities or embryonic lethality, highlighting its essential role in cellular homeostasis.

Overall, GOSR1 is a conserved, essential component of the cis-Golgi SNARE machinery that facilitates vesicle fusion and proper protein processing in the secretory pathway.