Recognition of lysine-rich peptide ligands by murine cortactin SH3 domain: CD, ITC, and NMR studies
Abstract
Cortactin is a ubiquitous actin-binding protein that regulates various aspects of cell dynamics and is implicated in the pathogenesis of human neoplasia. The sequence of cortactin contains a number of signaling motifs and an SH3 domain at the C-terminus, which mediates the interaction of the protein with several partners, including Shank2. A recombinant protein, comprising the murine cortactin SH3 domain fused to GST (GST-SH3(m-cort)), was prepared and used to assess the domain-binding affinity of potential peptide-ligands reproducing the proline-rich regions of human HPK1 and Shank2 proteins. The key residues involved in the SH3(m-cort) domain recognition were identified by three different approaches: non-immobilized ligand interaction assay by circular dichroism, isothermal titration calorimetry, and nuclear magnetic resonance. Our results show that the classical PxxPxK class II binding motif is not sufficient to mediate the interaction with GST-SH3(m-cort), an event that depends on the presence of additional basic residues located at either the N- or the C-terminus of the PxxPxK motif. Especially effective in promoting the peptide binding is a Lys residue at the -5 position, a determinant present in both P2 (HPK1 394-403) an...Continue Reading
References
Human HPK1, a novel human hematopoietic progenitor kinase that activates the JNK/SAPK kinase cascade
Citations
Related Concepts
Related Feeds
Actin-binding Proteins
Actin-binding proteins are a component of the actin cytoskeleton that play essential roles in cellular functions such as regulation of actin polymerization, maintenance of cell polarity, gene expression regulation, cell motility and many more functions. Discover the latest research on actin-binding proteins here.