General vesicular transport factor p115 is a protein that in humans is encoded by the USO1 gene. [5] [6] [7] [8] [9] [10]
The protein encoded by this gene is a peripheral membrane protein which recycles between the cytosol and the Golgi apparatus during interphase. It is regulated by phosphorylation: dephosphorylated protein associates with the Golgi membrane and dissociates from the membrane upon phosphorylation. Ras-associated protein 1 recruits this protein to coat protein complex II (COPII) vesicles during budding from the endoplasmic reticulum (ER), where it interacts with a set of COPII vesicle-associated SNAREs to form a cis-SNARE complex that promotes targeting to the Golgi apparatus. Transport from the ER to the cis/medial Golgi compartments requires the action of this gene product, GOLGA2, and giantin in a sequential manner. [10]
USO1 has been shown to interact with:
N-ethylmaleimide-sensitive factor, also known as NSF or N-ethylmaleimide sensitive fusion proteins, is an enzyme which in humans is encoded by the NSF gene.
COPII is a coatomer, a type of vesicle coat protein that transports proteins from the rough endoplasmic reticulum to the Golgi apparatus. This process is termed anterograde transport, in contrast to the retrograde transport associated with the COPI protein. The name "COPII" refers to the specific coat protein complex that initiates the budding process. The coat consists of large protein subcomplexes that are made of four different protein subunits.
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.
Coatomer subunit beta is a protein that in humans is encoded by the COPB1 gene.
Golgin subfamily A member 2 is a protein that in humans is encoded by the GOLGA2 gene.
Syntaxin-binding protein 1 is a protein that in humans is encoded by the STXBP1 gene. This gene encodes a syntaxin-binding protein. The encoded protein appears to play a role in release of neurotransmitters via regulation of syntaxin, a transmembrane attachment protein receptor. Mutations in this gene have been associated with infantile epileptic encephalopathy-4.
Ras-related protein Rab-1A is a protein that in humans is encoded by the RAB1A gene.
N-ethylmaleimide-sensitive factor Attachment Protein Alpha, also known as SNAP-α, is a SNAP protein that is involved in the intra-cellular trafficking and fusing of vesicles to target membranes in cells.
Golgi reassembly-stacking protein of 65 kDa (GRASP65) also known as Golgi reassembly-stacking protein 1 (GORASP1) is a protein that in humans is encoded by the GORASP1 gene.
Syntaxin-5 is a protein that in humans is encoded by the STX5 gene.
Synaptobrevin homolog YKT6 is a protein that in humans is encoded by the YKT6 gene.
Golgi SNAP receptor complex member 1 is a protein that in humans is encoded by the GOSR1 gene.
Golgi reassembly-stacking protein of 55 kDa (GRASP55) also known as golgi reassembly-stacking protein 2 (GORASP2) is a protein that in humans is encoded by the GORASP2 gene. It was identified by its homology with GRASP65 and the protein's amino acid sequence was determined by analysis of a molecular clone of its complementary DNA. The first (N-terminus) 212 amino acid residues of GRASP55 are highly homologous to those of GRASP65, but the remainder of the 454 amino acid residues are highly diverged from GRASP65. The conserved region is known as the GRASP domain, and it is conserved among GRASPs of a wide variety of eukaryotes, but not plants. The C-terminus portion of the molecule is called the SPR domain. GRASP55 is more closely related to homologues in other species, suggesting that GRASP55 is ancestral to GRASP65. GRASP55 is found associated with the medial and trans cisternae of the Golgi apparatus.
BET1-like protein is a protein that in humans is encoded by the BET1L gene.
Golgin subfamily A member 5 is a protein that in humans is encoded by the GOLGA5 gene.
BET1 homolog is a protein that in humans is encoded by the BET1 gene.
Sec1 family domain-containing protein 1 is a protein that in humans is encoded by the SCFD1 gene.
Golgi SNAP receptor complex member 2 is a protein that in humans is encoded by the GOSR2 gene.
Giantin or Golgin subfamily B member 1 is a protein that in humans is encoded by the GOLGB1 gene. Giantin is located at the cis-medial rims of the Golgi apparatus and is part of the Golgi matrix that is responsible for membrane trafficking in secretory pathway of proteins. This function is key for proper localisation of proteins at the plasma membrane and outside the cell which is important for cell function that is dependent on for example receptors and the extracellular matrix function. Recent animal model knockout studies of GOLGB1 in mice, rat, and zebrafish have shown that phenotypes are different between species ranging from mild to severe craniofacial defects in the rodent models to just minor size defects in zebrafish. However, in adult zebrafish a tumoral calcinosis-like phenotype was observed, and in humans such phenotype has been linked to defective glycosyltransferase function.
The Golgi matrix is a collection of proteins involved in the structure and function of the Golgi apparatus. The matrix was first isolated in 1994 as an amorphous collection of 12 proteins that remained associated together in the presence of detergent and 150 mM NaCl. Treatment with a protease enzyme removed the matrix, which confirmed the importance of proteins for the matrix structure. Modern freeze etch electron microscopy (EM) clearly shows a mesh connecting Golgi cisternae and associated vesicles. Further support for the existence of a matrix comes from EM images showing that ribosomes are excluded from regions between and near Golgi cisternae.