COPG2

COPG2 is the gene that encodes the coatomer protein complex subunit gamma-2, a component of the coatomer protein complex I (COPI). COPI is a multi-subunit coat involved in forming vesicles that mediate retrograde transport from the Golgi apparatus to the endoplasmic reticulum and in intra-Golgi trafficking. The gamma-2 subunit is a paralog of gamma-1-COP, encoded by COPG1, and both are part of the conserved COPI coatomer in eukaryotic cells.

Function and role in trafficking

As part of the COPI complex, the gamma-2 subunit contributes to coat assembly on budding vesicles, cargo selection, and proper vesicle formation. COPI coats are recruited to membranes by the ARF family of small GTPases, and the gamma-2 subunit collaborates with other COPI subunits to maintain Golgi structure and ensure efficient retrograde transport of resident enzymes and recycling of membrane components.

Genomic context and evolution

COPG2 belongs to a gene family with its paralog COPG1 (gamma-1-COP). In vertebrates, both COPG1 and COPG2 encode gamma-COP subunits that are incorporated into COPI complexes. The COPI system is highly conserved across eukaryotes, reflecting its fundamental role in intracellular trafficking.

Expression and clinical significance

COPG2 is expressed in multiple human tissues, consistent with a broad role in cellular trafficking. While disruptions in vesicular transport can have wide-ranging effects, there are no widely established, gene-specific disease associations for COPG2 in humans. As with other COPI components, experimental models indicate that proper COPI function is essential for cellular viability and normal development.

See also

Coatomer protein complex I, vesicular transport, Golgi apparatus, endoplasmic reticulum, ARF GTPases.