Characterization of a novel Ras-binding protein Ce-FLI-1 comprising leucine-rich repeats and gelsolin-like domains

Biochem Biophys Res Commun. 1999 Apr 2;257(1):111-6. doi: 10.1006/bbrc.1999.0420.

Abstract

Ras proteins are conserved from yeasts to mammals and implicated in regulation of the actin cytoskeleton. The flightless-1 (fli-1) gene of Drosophila melanogaster and its homologs in Caenorhabditis elegans and humans encode proteins (FLI-1) comprising a fusion of a leucine-rich repeats (LRRs) domain and a gelsolin-like domain. This LRRs domain is highly homologous to those of three proteins involved in Ras-mediated signaling; Saccharomyces cerevisiae adenylyl cyclase, C. elegans SUR-8, and mammalian RSP-1. Here we report that the LRRs domain of C. elegans FLI-1 (Ce-FLI-1) associates directly with Ras (Kd = 11 nM) and, when overexpressed, suppresses the heat shock sensitive phenotype of yeast cells bearing the activated RAS2 gene (RAS2(Val-19)). Further, the gelsolin-like domain of Ce-FLI-1 is shown to possess a Ca2+-independent G-actin-binding activity as well as F-actin-binding and -severing activities. FLI-1 may be involved in regulation of the actin cytoskeleton through Ras.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • Actins / ultrastructure
  • Adenylyl Cyclases / metabolism
  • Animals
  • Binding, Competitive
  • Caenorhabditis elegans / chemistry
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism*
  • Calcium / metabolism
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Dose-Response Relationship, Drug
  • Drosophila Proteins*
  • Egtazic Acid / pharmacology
  • Enzyme Activation / drug effects
  • Gelsolin / chemistry*
  • Gelsolin / genetics
  • Heat-Shock Response
  • Helminth Proteins / chemistry
  • Helminth Proteins / genetics
  • Helminth Proteins / metabolism*
  • Humans
  • Insect Proteins / chemistry
  • Insect Proteins / genetics
  • Insect Proteins / metabolism*
  • Leucine / chemistry*
  • Leucine / genetics
  • Oncogene Protein p21(ras) / antagonists & inhibitors
  • Oncogene Protein p21(ras) / metabolism*
  • Peptide Fragments / chemistry
  • Peptide Fragments / genetics
  • Peptide Fragments / metabolism
  • Peptide Fragments / pharmacology
  • Protein Binding / drug effects
  • Protein Biosynthesis
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Sequence Homology, Amino Acid

Substances

  • Actins
  • Carrier Proteins
  • Drosophila Proteins
  • Gelsolin
  • Helminth Proteins
  • Insect Proteins
  • Peptide Fragments
  • Recombinant Fusion Proteins
  • fliI protein, Drosophila
  • Egtazic Acid
  • Oncogene Protein p21(ras)
  • Adenylyl Cyclases
  • Leucine
  • Calcium