An actin-binding site containing a conserved motif of charged amino acid residues is essential for the morphogenic effect of villin.
The actin-binding protein villin induces microvillus growth and reorganization of the cytoskeleton in cells that do not normally produce this protein. Transfection of mutagenized villin cDNAs into CV-1 cells was used to show that a conserved, COOH-terminally located cluster of charged amino acid residues (KKEK) is crucial for the morphogenic activity of villin in vivo. In vitro experiments with a 22 amino acid synthetic peptide corresponding to this region of villin provide evidence that this motif is part of an F-actin-binding site that induces G-actin to polymerize. Chemical cross-linking of actin to this peptide, the effects of amino acid substitutions in peptides, and the behavior of villin variants further corroborate the participation of the KKEK sequence in actin contacts.
Friederich
E
E
Institut Pasteur URA 1149 CNRS, Département de Biologie Moléculaire, Paris, France.
Vancompernolle
K
K
Huet
C
C
Goethals
M
M
Finidori
J
J
Vandekerckhove
J
J
Louvard
D
D
D000199:Actins / Q000737:chemistry*; D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects*; D008840:Microfilament Proteins / Q000737:chemistry* / Q000494:pharmacology; D008969:Molecular Sequence Data; D009024:Morphogenesis; D009154:Mutation; D010446:Peptide Fragments / Q000138:chemical synthesis; D014162:Transfection
D000199:Actins; D002352:Carrier Proteins; D008840:Microfilament Proteins; D010446:Peptide Fragments; C026615:villin