SEC23A
Description
The SEC23A (SEC23 homolog A, COPII coat complex component) is a protein-coding gene located on chromosome 14.
The Coat Protein Complex II, or COPII, is a group of proteins that facilitate the formation of vesicles to transport proteins from the endoplasmic reticulum to the Golgi apparatus or endoplasmic-reticulum–Golgi intermediate compartment. This process is termed anterograde transport, in contrast to the retrograde transport associated with the COPI complex. COPII is assembled in two parts: first an inner layer of Sar1, Sec23, and Sec24 forms; then the inner coat is surrounded by an outer lattice of Sec13 and Sec31.
== Function == The COPII coat is responsible for the formation of vesicles from the endoplasmic reticulum (ER). These vesicles transport cargo proteins to the Golgi apparatus (in yeast) or the endoplasmic-reticulum-Golgi intermediate compartment (ERGIC, in mammals). Coat assembly is initiated when the cytosolic Ras GTPase Sar1 is activated by its guanine nucleotide exchange factor Sec12. Activated Sar1-GTP inserts itself into the ER membrane, binding preferentially to areas of membrane curvature. As Sar1-GTP inserts into the membrane, it recruits Sec23 and Sec24 to make up the inner cage. Once the inner coat is assembled, the outer coat proteins Sec13 and Sec31 are recruited to the budding vesicle. Hydrolysis of the Sar1 GTP to GDP promotes disassembly of the coat.
SEC23A is a component of the COPII protein complex, which plays a crucial role in the formation of transport vesicles from the endoplasmic reticulum (ER). COPII has two primary functions: physically shaping the ER membrane into vesicles and selecting cargo molecules for transport to the Golgi complex. SEC23A is essential for the translocation of insulin-induced glucose transporter SLC2A4/GLUT4 to the cell membrane.
SEC23A is also known as CLSD, hSec23A.
