Differential binding of ICln in platelets to integrin-derived activating and inhibitory peptides.

Abstract

The capacity of platelets to form a thrombus is mediated by integrin alpha(IIb)beta(3). The cytoplasmic tail of alpha(IIb) contains a highly conserved motif, (989)KVGFFKR(995), which plays a critical role in regulating integrin activation and acts as a recognition site for various intracellular proteins, e.g. CIB1, PP1, ICln and RN181. Previously, we demonstrated that a cell-permeable integrin-derived activating (IDA) peptide, KVGFFKR, induces platelet activation, whereas an integrin-derived inhibitory (IDI) peptide, KVGAAKR, is antithrombotic. To elucidate the molecular mechanism underlying these opposite effects we investigate the affinity of known integrin alpha(IIb) binding proteins for the two immobilized peptides in dependence on the activation state of platelets by means of peptide-affinity chromatography, blotting techniques and protein:peptide docking studies. Our results provide a model for the inhibition of ICln interaction with the integrin in activated platelets by the IDI-peptide. Thus, ICln:IDI-peptide interaction profiles can have a pivotal purpose in the search for consensus pharmacophores specifically inhibiting ICln function in platelets potentially leading to the development of integrin-derived antithrombotic drugs.

• Authors: Markus Raab, Laavanya Parthasarathi, Achim Treumann, Niamh Moran, Heide Daxecker
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 392 Issue 3 Pg. 258-63 (Feb 12 2010) ISSN: 1090-2104 [Electronic] United States
• PMID: 20034469 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• CLNS1A protein, human
• Ion Channels
• Oligopeptides
• Platelet Glycoprotein GPIIb-IIIa Complex
• Recombinant Proteins

Topics

• Amino Acid Motifs
• Amino Acid Sequence
• Blood Platelets (metabolism)
• Humans
• Ion Channels (agonists, antagonists & inhibitors, metabolism)
• Models, Molecular
• Molecular Sequence Data
• Oligopeptides (chemistry, genetics, metabolism)
• Platelet Glycoprotein GPIIb-IIIa Complex (chemistry, genetics, metabolism)
• Recombinant Proteins (agonists, antagonists & inhibitors, metabolism)
• Thrombosis (metabolism)