Diphosphorylation of the myosin regulatory light chain enhances the tension acting on stress fibers in fibroblasts.
Regulation of the contractile force is crucial for cell migration, cell proliferation, and maintenance of cell morphology. Phosphorylation of the myosin II regulatory light chain (MRLC) is involved in these processes. To show whether the diphosphorylation of MRLC increases the tension acting on stress fibers, changes in the stiffness of fibroblasts expressing wild-type MRLC and a mutant type, which cannot be diphosphorylated, on treatment with lysophosphatidic acid (LPA) were examined by a mechanical-scanning probe microscope (M-SPM). The LPA treatment increased cellular stiffness in the wild-type MRLC expressing cells, while it had no effect on the mutated cells. Immunostaining showed that LPA stimulation induced the diphosphorylation of MRLC. These results suggest that the diphosphorylation of MRLC enhances the tension acting on stress fibers.
Mizutani
Takeomi
T
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan. mizutani@sci.hokudai.ac.jp
Haga
Hisashi
H
Koyama
Yoshikazu
Y
Takahashi
Masayuki
M
Kawabata
Kazushige
K
D000818:Animals; D002478:Cells, Cultured; D005347:Fibroblasts / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism; D008246:Lysophospholipids / Q000494:pharmacology; D051379:Mice; D018994:Myosin Light Chains / Q000235:genetics / Q000378:metabolism*; D041681:NIH 3T3 Cells; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D022502:Stress Fibers / Q000378:metabolism*; D013314:Stress, Mechanical; D013718:Tensile Strength; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein / Q000235:genetics / Q000378:metabolism
D047908:Intracellular Signaling Peptides and Proteins; D008246:Lysophospholipids; D018994:Myosin Light Chains; D011993:Recombinant Fusion Proteins; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; C032881:lysophosphatidic acid