Functional analysis of calcium-binding EF-hand motifs of visinin-like protein-1

Biochem Biophys Res Commun. 2002 Aug 30;296(4):827-32. doi: 10.1016/s0006-291x(02)00943-9.

Abstract

Visinin-like protein-1 (VILIP-1), a myristoylated calcium sensor protein with three EF-hand motifs, modulates adenylyl cyclase activity. It translocates to membranes when a postulated "calcium-myristoyl switch" is triggered by calcium-binding to expose its sequestered myristoyl moiety. We investigated the contributions of the EF-hand motifs to the translocation of VILIP-1 to membranes and to the modulation of adenylyl cyclase activity. Mutation of residues crucial for binding calcium within each one of the EF-hand motifs indicated that they all contributed to binding calcium. Simultaneous mutations of all of the three EF-hand motifs completely abolished VILIP-1's ability to bind calcium, attenuated but did not eliminate its modulation of adenylyl cyclase activity, and abolished its calcium-dependence for association with cellular membranes. These results show that the calcium-binding EF-hand motifs of VILIP-1 do not have an essential role in modulating adenylyl cyclase activity but instead have a structural role in activating the "calcium-myristoyl switch" of VILIP-1.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adenylyl Cyclases / metabolism
  • Amino Acid Motifs
  • Calcium / metabolism
  • Calcium-Binding Proteins / chemistry*
  • Cell Line
  • Cyclic AMP / metabolism
  • Cytosol / metabolism
  • DNA, Complementary / metabolism
  • EF Hand Motifs
  • Humans
  • Immunohistochemistry
  • Microscopy, Fluorescence
  • Mutation
  • Myristic Acid / metabolism
  • Nerve Tissue Proteins / chemistry*
  • Neurocalcin
  • Polymerase Chain Reaction
  • Protein Conformation
  • Protein Structure, Tertiary
  • Receptors, Calcium-Sensing*
  • Recombinant Proteins / metabolism
  • Time Factors
  • Transfection

Substances

  • Calcium-Binding Proteins
  • DNA, Complementary
  • Nerve Tissue Proteins
  • Neurocalcin
  • Receptors, Calcium-Sensing
  • Recombinant Proteins
  • VSNL1 protein, human
  • Myristic Acid
  • Cyclic AMP
  • Adenylyl Cyclases
  • Calcium