COPA | |||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||||||||||||||||||||||||||||||||||||||||||
Identifiers | |||||||||||||||||||||||||||||||||||||||||||||||||||
Aliases | COPA , HEP-COP, AILJK, coatomer protein complex subunit alpha, alpha-COP, COPI coat complex subunit alpha | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | OMIM: 601924 MGI: 1334462 HomoloGene: 3218 GeneCards: COPA | ||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||
Wikidata | |||||||||||||||||||||||||||||||||||||||||||||||||||
|
Coatomer subunit alpha is a protein that in humans is encoded by the COPA gene. [4] [5]
In eukaryotic cells, protein transport between the endoplasmic reticulum and Golgi compartments is mediated in part by non-clathrin-coated vesicular coat proteins (COPs). Seven coat proteins have been identified, and they represent subunits of a complex known as coatomer. The subunits are designated alpha-COP, beta-COP, beta-prime-COP, gamma-COP, delta-COP, epsilon-COP, and zeta-COP. The alpha-COP, encoded by COPA, shares high sequence similarity with RET1, the homologous alpha subunit of the coatomer complex in yeast. [6] Also, the N-terminal 25 amino acids of alpha-COP encode the bioactive peptide, xenin, which stimulates exocrine pancreatic secretion and may act as a gastrointestinal hormone. Alternative splicing results in multiple splice forms encoding distinct isoforms. [5]
COPA (gene) has been shown to interact with COPE [7] [8] [9] and COPB1. [10]
COPI is a coatomer, a protein complex that coats vesicles transporting proteins from the cis end of the Golgi complex back to the rough endoplasmic reticulum (ER), where they were originally synthesized, and between Golgi compartments. This type of transport is retrograde transport, in contrast to the anterograde transport associated with the COPII protein. The name "COPI" refers to the specific coat protein complex that initiates the budding process on the cis-Golgi membrane. The coat consists of large protein subcomplexes that are made of seven different protein subunits, namely α, β, β', γ, δ, ε and ζ.
The coatomer is a protein complex that coats membrane-bound transport vesicles. Two types of coatomers are known:
ADP-ribosylation factor 1 is a protein that in humans is encoded by the ARF1 gene.
Coatomer subunit beta is a protein that in humans is encoded by the COPB1 gene.
Guanine nucleotide-binding protein G(z) subunit alpha is a protein that in humans is encoded by the GNAZ gene.
Regulator of G-protein signaling 19 is a protein that in humans is encoded by the RGS19 gene.
Coatomer subunit epsilon is a protein that in humans is encoded by the COPE gene.
Coatomer subunit beta is a protein that is encoded by the COPB2 gene in humans.
Coatomer subunit gamma-2 is a protein that in humans is encoded by the COPG2 gene.
Coatomer subunit gamma is a protein that in humans is encoded by the COPG gene. It is one of seven proteins in the COPI coatomer complex that coats vesicles as they bud from the Golgi complex.
ADP-ribosylation factor 5 is a protein that in humans is encoded by the ARF5 gene.
Mediator of RNA polymerase II transcription subunit 17 is an enzyme that in humans is encoded by the MED17 gene.
Conserved oligomeric Golgi complex subunit 7 is a protein that in humans is encoded by the COG7 gene.
Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-3 is a protein that in humans is encoded by the GNG3 gene.
Protein transport protein Sec61 subunit alpha isoform 1 is a protein that in humans is encoded by the SEC61A1 gene.
Conserved oligomeric Golgi complex subunit 1 is a protein that in humans is encoded by the COG1 gene.
Coatomer subunit zeta-1 is a protein that in humans is encoded by the COPZ1 gene.
Caveolin-2 is a protein that in humans is encoded by the CAV2 gene.
Clathrin adaptor proteins, also known as adaptins, are vesicular transport adaptor proteins associated with clathrin. These proteins are synthesized in the ribosomes, processed in the endoplasmic reticulum and transported from the Golgi apparatus to the trans-Golgi network, and from there via small carrier vesicles to their final destination compartment. The association between adaptins and clathrin are important for vesicular cargo selection and transporting. Clathrin coats contain both clathrin and adaptor complexes that link clathrin to receptors in coated vesicles. Clathrin-associated protein complexes are believed to interact with the cytoplasmic tails of membrane proteins, leading to their selection and concentration. Therefore, adaptor proteins are responsible for the recruitment of cargo molecules into a growing clathrin-coated pits. The two major types of clathrin adaptor complexes are the heterotetrameric vesicular transport adaptor proteins (AP1-5), and the monomeric GGA adaptors. Adaptins are distantly related to the other main type of vesicular transport proteins, the coatomer subunits, sharing between 16% and 26% of their amino acid sequence.
The C-terminal domain ofBeta2-adaptin is a protein domain is involved in cell trafficking by aiding import and export of substances in and out of the cell.