Giantin or Golgin subfamily B member 1 is a
protein that in humans is encoded by the GOLGB1gene.[5][6][7] 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 (extracellular region) 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,[8]rat,[9] and
zebrafish[10] 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 (e.g.
GALNT3 protein).[11]
Function and Interactions
Giantin is a disulfide-linked
homodimer which contains several (around 37) coiled-coiled domains. GOLGB1 protein has been shown to
interact with
ACBD3 and with
PLK3[12] and vesicle tethering small GTPases Rab1 and Rab6.[13] Giantin also interacts with P115 at the N-terminal coils facilitating binding to the other Golgi matrix protein
GM130[14] that is thought to be important for Golgi secretory function. Loss-of function studies of giantin have also suggested a role in
primary cilia[15][16] function and defective regulation of
glycosyltransferase expression and
calcineurin signalling in tissue culture cells.[17][18]
Sohda M, Misumi Y, Fujiwara T, et al. (1995). "Molecular cloning and sequence analysis of a human 372-kDA protein localized in the Golgi complex". Biochem. Biophys. Res. Commun. 205 (2): 1399–408.
doi:
10.1006/bbrc.1994.2821.
PMID7802676.
Seelig HP, Schranz P, Schröter H, et al. (1994). "Macrogolgin--a new 376 kD Golgi complex outer membrane protein as target of antibodies in patients with rheumatic diseases and HIV infections". J. Autoimmun. 7 (1): 67–91.
doi:
10.1006/jaut.1994.1006.
PMID8198703.
Rosing M, Ossendorf E, Rak A, Barnekow A (2007). "Giantin interacts with both the small GTPase Rab6 and Rab1". Exp. Cell Res. 313 (11): 2318–25.
doi:
10.1016/j.yexcr.2007.03.031.
PMID17475246.
Giantin or Golgin subfamily B member 1 is a
protein that in humans is encoded by the GOLGB1gene.[5][6][7] 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 (extracellular region) 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,[8]rat,[9] and
zebrafish[10] 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 (e.g.
GALNT3 protein).[11]
Function and Interactions
Giantin is a disulfide-linked
homodimer which contains several (around 37) coiled-coiled domains. GOLGB1 protein has been shown to
interact with
ACBD3 and with
PLK3[12] and vesicle tethering small GTPases Rab1 and Rab6.[13] Giantin also interacts with P115 at the N-terminal coils facilitating binding to the other Golgi matrix protein
GM130[14] that is thought to be important for Golgi secretory function. Loss-of function studies of giantin have also suggested a role in
primary cilia[15][16] function and defective regulation of
glycosyltransferase expression and
calcineurin signalling in tissue culture cells.[17][18]
Sohda M, Misumi Y, Fujiwara T, et al. (1995). "Molecular cloning and sequence analysis of a human 372-kDA protein localized in the Golgi complex". Biochem. Biophys. Res. Commun. 205 (2): 1399–408.
doi:
10.1006/bbrc.1994.2821.
PMID7802676.
Seelig HP, Schranz P, Schröter H, et al. (1994). "Macrogolgin--a new 376 kD Golgi complex outer membrane protein as target of antibodies in patients with rheumatic diseases and HIV infections". J. Autoimmun. 7 (1): 67–91.
doi:
10.1006/jaut.1994.1006.
PMID8198703.
Rosing M, Ossendorf E, Rak A, Barnekow A (2007). "Giantin interacts with both the small GTPase Rab6 and Rab1". Exp. Cell Res. 313 (11): 2318–25.
doi:
10.1016/j.yexcr.2007.03.031.
PMID17475246.