Analysis of the CD23-αv integrin interaction: A study with model peptides

• Published in: Biochemical and biophysical research communications 2012-06, Vol.422 (2), p.207-212
• Main Authors: Edkins, Adrienne L., Borland, Gillian, Kelly, Sharon M., Cogdell, Richard J., Ozanne, Bradford W., Cushley, William
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino Acid Substitution; CD23; Cell Line; Humans; Integrin alphaV - chemistry; Integrin alphaV - metabolism; Integrin alphaVbeta3 - chemistry; Integrin alphaVbeta3 - metabolism; Peptide Fragments - chemistry; Peptide Fragments - genetics; Peptide Fragments - metabolism; Receptors, IgE - chemistry; Receptors, IgE - genetics; Receptors, IgE - metabolism; Receptors, Vitronectin - chemistry; Receptors, Vitronectin - metabolism; Surface Plasmon Resonance; αv Integrins
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2012.04.076

► αvβ3 and αvβ5 integrins bind the human CD23 protein via an RKC motif. ► The interaction of αv integrins and CD23 is cation-independent. ► Single substitutions in RKC do not abolish integrin binding or biological function. ► Integrin binding of RKC and RGD motifs have distinctive characteristics. The human CD23 protein binds to αvβ3 and αvβ5 integrins. The integrins recognize a short tripeptide motif of arg-lys-cys (RKC) in CD23, and peptides containing this motif inhibit the binding of CD23 to B cells and monocytes; neither fibronectin, nor vitronectin, which contain arg-gly-asp motifs, inhibit binding of RKC-containing peptides to cells. RKC-containing peptides derived from CD23 show dose-dependent, biphasic binding profiles to both αvβ3 and αvβ5 that are cation-independent but sensitive to high chloride ion concentrations. Substitution of one basic residue in the RKC motif with alanine reduces but does not abolish integrin binding or the ability of peptides to stimulate pre-B cell growth or cytokine release by monocytes. Substitution of both basic residues abolishes both integrin binding and biological activity of CD23-derived peptides. These features indicate that binding of RKC-containing peptides to αv integrins has clearly distinct characteristics to those for binding of RGD-containing ligands.