Identification of cofilin and LIM-domain-containing protein kinase 1 as novel interaction partners of 14-3-3 zeta

• Published in: Biochemical journal Vol. 369; no. Pt 1; pp. 45 - 54
• Main Authors: Birkenfeld, Jörg, Betz, Heinrich, Roth, Dagmar
• Format: Journal Article
• Language: English
• Published: England 01.01.2003
• Subjects: 14-3-3 Proteins; Actin Depolymerizing Factors; Animals; Base Sequence; Cell Line; COS Cells; DNA Primers; DNA-Binding Proteins - metabolism; Humans; Immunohistochemistry; Lim Kinases; Microfilament Proteins - metabolism; Protein Binding; Protein Kinases; Protein-Serine-Threonine Kinases - metabolism; Rats; Two-Hybrid System Techniques; Tyrosine 3-Monooxygenase - metabolism
• DOI: 10.1042/BJ20021152
• ISSN: 0264-6021

Proteins of the 14-3-3 family have been implicated in various physiological processes, and are thought to function as adaptors in various signal transduction pathways. In addition, 14-3-3 proteins may contribute to the reorganization of the actin cytoskeleton by interacting with as yet unidentified actin-binding proteins. Here we show that the 14-3-3 zeta isoform interacts with both the actin-depolymerizing factor cofilin and its regulatory kinase, LIM (Lin-11/Isl-1/Mec-3)-domain-containing protein kinase 1 (LIMK1). In both yeast two-hybrid assays and glutathione S-transferase pull-down experiments, these proteins bound efficiently to 14-3-3 zeta. Deletion analysis revealed consensus 14-3-3 binding sites on both cofilin and LIMK1. Furthermore, the C-terminal region of 14-3-3 zeta inhibited the binding of cofilin to actin in co-sedimentation experiments. Upon co-transfection into COS-7 cells, 14-3-3 zeta-specific immunoreactivity was redistributed into characteristic LIMK1-induced actin aggregations. Our data are consistent with 14-3-3-protein-induced changes to the actin cytoskeleton resulting from interactions with cofilin and/or LIMK1.