The glycoprotein hGC-1 binds to cadherin and lectins.
Human granulocyte colony stimulating factor stimulated clone-1 (hGC-1, also known as GW112, OLM4, and hOlfD) is an olfactomedin-related glycoprotein of unknown function. We performed a series of biochemical studies to characterize its function. Using hGC-1 purified from baculovirus Sf9 cells we demonstrated that hGC-1 is a secreted glycoprotein containing N-linked carbohydrate chains and forms disulfide-bonded multimers. It binds to cell surfaces and to the locutions ricinus communis agglutinin I, concanavalin A and wheat germ agglutinin. Purified hGC-1 enhanced NIH3T3 and 293T/17 cell spreading and attachment, as did hGC-1-enriched culture supernatants of 293T/17 cells transfected with an hGC-1 expression vector. Coimmunoprecipitation studies demonstrated that hGC-1 interacts with cadherin in 293T/17 cells. This interaction depends on the C-terminal olfactomedin domain, but does not require the five well-conserved cysteine residues. However, cysteine residues at 83, 85, 246 and 437 are essential for secretion, and cysteine 226 is critical for hGC-1 multimer formation. Our studies demonstrated that hGC-1, an extracellular matrix glycoprotein, facilitates cell adhesion. Its potential interaction with endogenous cell surface lectins and cadherin may mediate this function.
Molecular and Clinical Hematology Branch, National Institute of Diabetes, Digestive, and Kidney Diseases, National Institutes of Health, Bldg.10, Room 9N119, 9000 Rockville Pike, Bethesda, MD 20892, USA.
Wenli
W
Liu
Ling
L
Chen
Jianchong
J
Zhu
Griffin P
GP
Rodgers
D000818:Animals; D015820:Cadherins / Q000378:metabolism*; D002448:Cell Adhesion; D002460:Cell Line; D003545:Cysteine / Q000378:metabolism; D016179:Granulocyte Colony-Stimulating Factor / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D051379:Mice; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011869:Radioligand Assay; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D015820:Cadherins; D037102:Lectins; C454127:OLFM4 protein, human; D011994:Recombinant Proteins; D016179:Granulocyte Colony-Stimulating Factor; D003545:Cysteine