Phosphorylation of cofilin by LIM-kinase is necessary for semaphorin 3A-induced growth cone collapse.
Semaphorin 3A is a chemorepulsive axonal guidance molecule that depolymerizes the actin cytoskeleton and collapses growth cones of dorsal root ganglia neurons. Here we investigate the role of LIM-kinase 1, which phosphorylates an actin-depolymerizing protein, cofilin, in semaphorin 3A-induced growth cone collapse. Semaphorin 3A induced phosphorylation and dephosphorylation of cofilin at growth cones sequentially. A synthetic cell-permeable peptide containing a cofilin phosphorylation site inhibited LIM-kinase in vitro and in vivo, and essentially suppressed semaphorin 3A-induced growth cone collapse. A dominant-negative LIM kinase, which could not be activated by PAK or ROCK, suppressed the collapsing activity of semaphorin 3A. Phosphorylation of cofilin by LIM-kinase may be a critical signaling event in growth cone collapse by semaphorin 3A.
Department of Cell Biology, Tokyo Metropolitan Institute of Medical Science, Honkomagome 3-18-22, Bunkyo-ku, Tokyo 113-8613, Japan. aizawa@rr.iij4u.or.jp
H
H
Aizawa
S
S
Wakatsuki
A
A
Ishii
K
K
Moriyama
Y
Y
Sasaki
K
K
Ohashi
Y
Y
Sekine-Aizawa
A
A
Sehara-Fujisawa
K
K
Mizuno
Y
Y
Goshima
I
I
Yahara
D051339:Actin Depolymerizing Factors; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002478:Cells, Cultured; D005727:Ganglia, Spinal / Q000166:cytology; D005822:Genetic Vectors / Q000235:genetics; D006023:Glycoproteins / Q000378:metabolism*; D020439:Growth Cones / Q000502:physiology* / Q000648:ultrastructure; D006801:Humans; D054461:Lim Kinases; D051379:Mice; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009414:Nerve Growth Factors / Q000378:metabolism; D009475:Neurons, Afferent / Q000166:cytology / Q000201:enzymology*; D010455:Peptides / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D040121:Semaphorin-3A; D014162:Transfection
D051339:Actin Depolymerizing Factors; D000199:Actins; D006023:Glycoproteins; D008840:Microfilament Proteins; D009414:Nerve Growth Factors; D010455:Peptides; D011994:Recombinant Proteins; D040121:Semaphorin-3A; D011494:Protein Kinases; C515892:LIMK1 protein, human; D054461:Lim Kinases; C515893:Limk1 protein, mouse