Identification of a Calmodulin-Binding and Inhibitory Peptide Domain in the HIV-1 Transmembrane Glycoprotein

Mark A. Miller, Timothy A. Mietzner, Miles W. Cloyd, W. Gerard Robey, Ronald C. Montelaro

Research output: Contribution to journalArticle

57 Scopus citations

Abstract

A number of studies suggest a critical role of the HIV-1 envelope glycoprotein in cytopathogenesis, but the detailed mechanisms of cell injury remain to be defined. HIV-1 envelope proteins associate with the host cell membrane, and studies have demonstrated that HIV perturbs membrane structure and function. We describe here a structurally conserved region of the HIV-1 transmembrane protein (TM) that displays functional properties of target regions of proteins that interact directly with calcium-saturated calmodulin as part of cellular response cascades. The synthetic peptide homolog encompassing the carboxyl terminus (amino acid residues 828–855) of HIV-1 TM protein (LLP-1) is shown in standard in vitro assays to bind efficiently to purified calmodulin (CaM) and to inhibit in vitro CaM-mediated stimulation of phosphodiesterase activity. This suggests that this peptide homolog binds to CaM at affinities similar to those reported for a reference CaM-binding peptide. In addition, the CaM-dependent process of phospholipid synthesis can be inhibited in cell cultures by exogenous addition of the LLP-1. Finally, we have shown that the full-length TM protein binds CaM, whereas a truncated TM protein lacking the LLP-1 segment does not bind CaM. These results suggest a novel mechanism of viral cytopathogenesis mediated by the interaction of HIV-1 TM protein with cellular CaM, that could lead to an uncoupling of critical cellular signal transduction pathways.

Original languageEnglish (US)
Pages (from-to)1057-1066
Number of pages10
JournalAIDS Research and Human Retroviruses
Volume9
Issue number11
DOIs
StatePublished - Nov 1993

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ASJC Scopus subject areas

  • Immunology
  • Virology
  • Infectious Diseases

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