BET1L

Bet1L is a human gene encoding a Bet1-like protein, a member of the SNARE superfamily involved in membrane fusion. It functions as a component of the ER-to-Golgi SNARE complex that mediates fusion of COPII-derived vesicles with Golgi membranes, enabling progression of cargo proteins through the secretory pathway. In vertebrates, Bet1L is believed to pair with other SNAREs—STX5 (syntaxin 5), GOSR1 (membrin), and SEC22B—to form a SNARE complex necessary for vesicle fusion at the early Golgi and ER-Golgi intermediate compartment. Bet1L localizes to the Golgi apparatus and to ER-Golgi intermediate compartments; it is a small, coiled-coil transmembrane protein anchored in membranes, with the cytosolic SNARE motif driving complex formation.

Bet1L is a mammalian ortholog of the yeast Bet1 protein. The Bet1 family is broadly conserved among eukaryotes, reflecting its role in fundamental intracellular trafficking processes. In cellular studies, depletion or disruption of Bet1L can perturb Golgi structure and trafficking of secretory proteins, highlighting its role in maintaining efficient ER-to-Golgi transport.

As of current understanding, Bet1L is primarily characterized for its role in intracellular transport rather than being linked to a specific human disease. Ongoing research continues to define its precise regulatory interactions and its contribution to Golgi dynamics, organelle homeostasis, and secretory pathway efficiency.