A Drosophila homolog of LIM-kinase phosphorylates cofilin and induces actin cytoskeletal reorganization

Biochem Biophys Res Commun. 2000 Oct 5;276(3):1178-85. doi: 10.1006/bbrc.2000.3599.

Abstract

Mammalian LIM-kinases (LIMKs) phosphorylate cofilin and induce actin cytoskeletal reorganization. To elucidate the functional roles of LIMKs in vivo during developmental processes, we attempted to isolate the cDNA encoding a Drosophila homolog of LIMK (DLIMK) and identified two isoforms of DLIMK transcripts coding for proteins with 1235 and 1257 amino acids, possessing the structure composed of two LIM domains, a PDZ domain, a protein kinase domain, and an unusual long C-terminal extension. In situ hybridization analysis in Drosophila embryos detected the uniformly distributed DLIMK mRNA in stages 2 to 5. In vitro kinase reaction revealed that DLIMK efficiently phosphorylates Drosophila cofilin (twinstar) specifically at Ser-3, the site responsible for inactivation of its actin-depolymerizing activity. When expressed in cultured cells, wild-type DLIMK, but not its kinase-inactive form, induced changes in actin cytoskeletal organization. These observations suggest that the LIMK-cofilin signaling pathway for regulating actin filament dynamics is evolutionarily conserved between Drosophila and mammals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actin Depolymerizing Factors
  • Actins / metabolism*
  • Amino Acid Sequence
  • Animals
  • COS Cells
  • Cloning, Molecular
  • Cytoskeleton / metabolism*
  • Drosophila melanogaster / embryology
  • Drosophila melanogaster / enzymology*
  • Embryo, Nonmammalian / enzymology
  • Expressed Sequence Tags
  • Gene Expression Regulation, Developmental
  • HeLa Cells
  • Humans
  • In Situ Hybridization
  • Lim Kinases
  • Microfilament Proteins / metabolism*
  • Molecular Sequence Data
  • Phosphorylation
  • Protein Kinases / chemistry
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • RNA, Messenger / analysis
  • RNA, Messenger / genetics
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment
  • Sequence Homology
  • Transfection

Substances

  • Actin Depolymerizing Factors
  • Actins
  • Microfilament Proteins
  • RNA, Messenger
  • Recombinant Fusion Proteins
  • Protein Kinases
  • LIMK1 protein, human
  • Lim Kinases

Associated data

  • GENBANK/AB042816
  • GENBANK/AB042818