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.
Liu
Wenli
W
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.
Chen
Ling
L
Zhu
Jianchong
J
Rodgers
Griffin P
GP
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