Gamma1COP

gamma1-COP, also known as gamma1-COP or gamma1COP, is a subunit of the coatomer protein complex I (COPI), which coats vesicles that mediate retrograde transport from the Golgi apparatus back to the endoplasmic reticulum. In humans it is encoded by the COPG1 gene. As a component of the COPI coat, gamma1-COP participates in coat assembly and cargo selection during vesicle formation at the Golgi.

Its primary role is in COPI vesicle formation and function, assisting in the retrieval of ER-resident proteins and other Golgi residents by contributing to cargo recognition and coat stability. The recruitment of COPI to membranes is regulated by the small GTPase ARF1; gamma1-COP participates in recognizing sorting signals on cargo and interacting with other COPI subunits to drive vesicle budding and trafficking.

Gamma1-COP has a closely related paralog, gamma2-COP, encoded by COPG2. These paralogs are part of the same subfamily of coatomer subunits and show overlapping but not identical expression patterns across tissues and developmental stages. COPG1 and COPG2 are conserved among eukaryotes, reflecting an essential role in Golgi and ER-Golgi trafficking.

In cell biology, gamma1-COP is essential for COPI function; disruption of COPI subunits, including gamma1-COP, impairs retrograde transport and can alter Golgi morphology and glycoprotein processing. While direct links to specific human diseases are limited, studies in model systems highlight its importance for proper intracellular trafficking and protein homeostasis.