Cloning, characterization, and functional studies of a nonintegrin platelet receptor for type I collagen.

Abstract

A cDNA (1.6 kb) encoding a platelet protein receptor that binds type I collagen has been isolated from a human bone marrow cDNA library by using a degenerate oligonucleotide probe derived from the amino acid sequence of a CNBr fragment of the purified receptor.

Platelet adhesion signalling and the regulation of thrombus formation

“…Furthermore, in the presence of α2β1-and GPV-blocking antibodies, mouse platelets that possess approximately 20% of the normal levels of GPVI-FcRγ respond to collagen but not to collagen-related peptide (a GPVI-selective ligand, see below) (Poole et al, 1997;Snell et al, 2002). Several additional putative platelet collagen receptors have been reported, including 68 kDa (Monnet et al, 2001;Monnet and Fauvel-Lefeve, 2000) and 65 kDa (Chiang et al, 1997) binding proteins for type III collagen, and a 47 kDa type I collagen-binding species (Chiang et al, 2002). It is unclear whether any of these contribute to platelet signalling, although some may have supporting roles and modulate GPVImediated responses.…”

A synthetic peptide derived from the sequence of a type I collagen receptor inhibits type I collagen-mediated platelet aggregation.

“…Since peptide-1 contains two tyrosine residues in the sequence, we radiolabeled the peptide by iodination using the chloramine T method (23). Microtiter wells were coated with type I collagen, type III collagen, or fibronectin, followed by 0.1% BSA as described previously (14).…”

“…The attached platelets were detached with 10 ml ScintiVerse BD (2 ml per time). Radioactivity was assessed with a Packard Scintillation counter (Packard, Downers Grove, IL) (14).…”

“…A recombinant protein was obtained from a prokaryotic expression vector. The recombinant protein binds to type I collagen and inhibits type I collagen-induced platelet aggregation and the release of ATP in a dose-dependent manner (14).…”

Ophioluxin, a Convulxin-like C-type Lectin from Ophiophagus hannah (King Cobra) Is a Powerful Platelet Activator via Glycoprotein VI

“…A large number of different receptors have been proposed for collagen on platelets, including CD36 (glycoprotein (GP) 1 IV, GPIIIb) (1), GPIb-V-IX complex as an indirect collagen receptor acting via von Willebrand factor (2), a 65-kDa collagen type I specific receptor (3), and a 68 -72-kDa doublet collagen type III-specific receptor (4), but the major ones have been identified as the integrin ␣ 2 ␤ 1 and Ig superfamily member GPVI. Integrin ␣ 2 ␤ 1 belongs to the class containing an I-domain, which has been well characterized and is considered to be responsible for platelet adhesion to collagen rather than platelet activation (5, 6) for which GPVI is largely responsible.…”