ORGANELLE MARKERS - Golgi

GS28

GS28, also known as p28 or GOS28, is a 28 kDa integral membrane protein on the surface of the Golgi apparatus that serves as a t- SNARE in ER to Golgi transport. The amino-terminal of GS28/GOS28 is exposed to the cytosol and is anchored to ths cis Golgi via a 20 amino acid carboxyl-terminal hydrophobic tail. GS28 co-immunoprecipitates complexes consisting of syntaxin 5, rbet1, membrin, rsec22, and rsly1, and is therefore implicated in ERto- Golgi or intra-Golgi vesicle transport. ATP hydrolysis by NSF in the presence of SNAP causes the dissociation of GOS28 and syntaxin 5 complex.

back

KDEL

KDEL receptor is a 26 kDa integral membrane protein that is responsible for the retrieval of soluble ER luminal proteins bearing the tetrapeptide, KDEL, from the Golgi apparatus. KDEL receptor exhibits extensive sequence identity to yeast protein Erd2p, which is a receptor for proteins containing the tetrapeptide HDEL, the yeast ER retention signal. KDEL receptor is localized to the cis Golgi and the intermediate compartments. KDEL receptor interacts with the GTPase-activating protein (GAP) of ARF1, a small GTP-binding protein involves in COPI-dependent vesicle transport. KDEL receptor may recruit cytosolic ARF1 to membranes and regulate vesicle budding.

back

Syntaxin 6

Syntaxin 6 is a 35 kDa type II integral membrane protein with two coiled-coil domains and a carboxyl-terminal membrane anchor (2). Immunoelectron microscopy studies show that syntaxin 6 is primarily localized to the trans-Golgi network (TGN), and is partially co-localized with AP-1 on clathrincoated membranes. During secretory granule maturation, syntaxin 6 and MPR-ligand complexes are postulated to be transferred from immature granules to endosomes by clathrincoated vesicles, as evidenced by immunoelectron microscopy . These results suggest that syntaxin 6 mediates a TGN trafficking targeting endosome.

back

TGN38

Recognizes a glycoprotein designated TGN38 that is found primarily in the Trans-Golgi network and has been found to be an excellent marker for this cellular organelle. TGN38 is likely to have a role in intracellular transport.

back

Rbet1

Rbet1 is a 17 kDa transmembrane protein that mediates protein transport between endoplasmic reticulum (ER) and the Golgi
apparatus. rBet1 serves as the vesicle SNAP receptor (v-SNARE) on ER-derived vesicles, which interacts with its partner t-SNARE on
the Golgi apparatus during vesicle docking and fusion. rBet1 is found in a complex with syntaxin 5, GS27/membrin, GOS28, rsec22 and
rsly1. Antibodies to rBet1 have been shown to inhibit the transfer of vesicular stomatitis virus G-protein from the ER to the
Golgi apparatus in a cell free assay, providing evidence for the involvement of rBet1 in ER to Golgi transport.

back

K58 Golgi Protein

58K protein antibodies are excellent for use as markers for the Golgi complex. The 58K protein has been identified as being FTCD, a bifunctional enzyme that channels 1-carbon units from formiminoglutamate, a metabolite of the histidine degradation pathway, to the folate pool.back

Mannosidase II

Mannosidase II is a 135kD protein located on the luminal side of the Golgi membranes. It is useful as an immunocytochemical marker for the Golgi apparatus as well as for studying the fate of the Golgi complex in dividing cells.

back

Golgi

This antibody can be used to stain the Golgi zone and can be used as a marker of the Golgi zone in subcellular fractions.

 back