RRC ID |
6475
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Author |
Amano T, Tanabe K, Eto T, Narumiya S, Mizuno K.
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Title |
LIM-kinase 2 induces formation of stress fibres, focal adhesions and membrane blebs, dependent on its activation by Rho-associated kinase-catalysed phosphorylation at threonine-505.
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Journal |
Biochem J
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Abstract |
LIM-kinase 1 and 2 (LIMK1 and LIMK2) phosphorylate cofilin and induce actin cytoskeletal reorganization. LIMK1 is activated by Rho-associated, coiled-coil-forming protein kinase (ROCK) and p21-activated kinase 1 (PAK1), but activation mechanisms and cellular functions of LIMK2 have remained to be determined. We report here that LIMK1 and LIMK2 phosphorylate both cofilin and actin-depolymerizing factor (ADF) specifically at Ser-3 and exhibit partially distinct substrate specificity when tested using site-directed cofilin mutants as substrates. We also show that LIMK2 is activated by ROCK by phosphorylation at Thr-505 within the activation loop. Wild-type LIMK2, but not its mutant (T505V) with replacement of Thr-505 by Val, was activated by ROCK in vitro and in vivo. LIMK2 mutants with replacement of Thr-505 by one or two Glu residues (T505E or T505EE) increased the kinase activity about 3.6-fold but were not further activated by ROCK. When expressed in HeLa cells, wild-type LIMK2, but not the T505V mutant, induced the formation of stress fibres, focal adhesions and membrane blebs. Furthermore, inhibitors of Rho and ROCK significantly suppressed LIMK2-induced stress fibres and membrane blebs. These results suggest that LIMK2 functions downstream of the Rho-ROCK signalling pathway and plays a role in reorganization of actin filaments and membrane structures, by phosphorylating cofilin/ADF proteins.
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Volume |
354(Pt 1)
|
Pages |
149-59
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Published |
2001-2-15
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DOI |
10.1042/0264-6021:3540149
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PMID |
11171090
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PMC |
PMC1221639
|
MeSH |
Actin Depolymerizing Factors
Actins / metabolism
Animals
Base Sequence
COS Cells
Cytoskeleton / ultrastructure*
DNA Primers
Enzyme Activation
HeLa Cells
Humans
Lim Kinases
Microfilament Proteins / metabolism
Phosphorylation
Protein Kinases / chemistry
Protein Kinases / metabolism*
Substrate Specificity
Threonine / metabolism*
|
IF |
4.097
|
Times Cited |
125
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WOS Category
|
BIOCHEMISTRY & MOLECULAR BIOLOGY
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Resource |
Human and Animal Cells |
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