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

作者：Ohashi K; Hosoya T; Takahashi K; Hing H; Mizuno K^*

来源：Biochemical and Biophysical Research Communications, 2000, 276(3): 1178-1185.

DOI：10.1006/bbrc.2000.3599

• LIM-kinase
• cofilin
• twinstar
• Drosophila
• actin reorganization
• in situ hybridization

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.

• 出版日期2000-10-5