Sec22b

Sec22b, also known as SEC22B, is a member of the SNARE protein family that participates in vesicular transport within the secretory pathway. In mammals, Sec22b is associated with the endoplasmic reticulum and the early secretory network, contributing to the trafficking of cargo from the ER toward the Golgi apparatus.

As a SNARE protein, Sec22b functions as part of a membrane fusion complex. It is thought to serve as the vesicle-associated component that pairs with target-mmembrane SNAREs to drive fusion events in ER-to-Golgi transport. In cells, Sec22b is often discussed in the context of forming SNARE complexes with other components such as syntaxin family members and related proteins, enabling cargo to move through the early secretory pathway.

Structurally, Sec22b is a membrane-anchored protein characterized by a single C-terminal transmembrane domain and a cytosolic SNARE motif essential for complex formation and membrane fusion. This configuration is typical of v-SNAREs that reside on transport vesicles and interact with t-SNAREs on target membranes.

Beyond ER-to-Golgi transport, some studies have explored additional roles for Sec22b in processes like autophagy and membrane trafficking in specialized cellular contexts, but its primary and most consistently described function lies in facilitating ER-to-Golgi cargo transport. SEC22B is broadly expressed, with tissue-specific differences in expression levels.

Sec22b is conserved across many eukaryotes, reflecting the essential nature of SNARE-mediated vesicle fusion in the secretory pathway.