Tyrosine phosphorylation induced by C4 peptide constructs from HIV Gp120

Treatment of HUT78 cells with CD4-binding peptide constructs derived from t he C4 domain of HIV-1 gp120 results in autophosphorylation of a src-related kinase, p56(lck). This leads to p56(lck) activation and the subsequent pho sphorylation of tyrosine residues in several intracellular proteins. The ph osphorylation is specific to the C4 peptides as no new phosphorylation occu rs when the cells are treated with control peptides or polymers. The induct ion of tyrosine phosphorylation by the C4 peptide constructs depends on the capability of the peptide to assume a helical conformation because similar peptide constructs that were not able to form helices did not induce cellu lar tyrosine phosphorylation. (C) 1999 Elsevier Science Inc. All rights res erved.