Distinct roles of MLCK and ROCK in the regulation of membrane protrusions and focal adhesion dynamics during cell migration of fibroblasts.
We examined the role of regulatory myosin light chain (MLC) phosphorylation of myosin II in cell migration of fibroblasts. Myosin light chain kinase (MLCK) inhibition blocked MLC phosphorylation at the cell periphery, but not in the center. MLCK-inhibited cells did not assemble zyxin-containing adhesions at the periphery, but maintained focal adhesions in the center. They generated membrane protrusions all around the cell, turned more frequently, and migrated less effectively. In contrast, Rho-associated kinase (ROCK) inhibition blocked MLC phosphorylation in the center, but not at the periphery. ROCK-inhibited cells assembled zyxin-containing adhesions at the periphery, but not focal adhesions in the center. They moved faster and more straight. On the other hand, inhibition of myosin phosphatase increased MLC phosphorylation and blocked peripheral membrane ruffling, as well as turnover of focal adhesions and cell migration. Our results suggest that myosin II activated by MLCK at the cell periphery controls membrane ruffling, and that the spatial regulation of MLC phosphorylation plays critical roles in controlling cell migration of fibroblasts.
Totsukawa
Go
G
Department of Molecular Biology and Biochemistry, Rutgers University, Nelson Labs, Rm. A323, 604 Allison Rd., Piscataway, NJ 08855, USA.
Wu
Yue
Y
Sasaki
Yasuharu
Y
Hartshorne
David J
DJ
Yamakita
Yoshihiko
Y
Yamashiro
Shigeko
S
Matsumura
Fumio
F
D000199:Actins / Q000378:metabolism; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D002465:Cell Movement / Q000502:physiology*; D048429:Cell Size; D022081:Cell Surface Extensions / Q000378:metabolism*; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D005350:Fibroma; D022001:Focal Adhesions / Q000378:metabolism*; D005849:Gerbillinae; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D018715:Microscopy, Video; D009219:Myosin-Light-Chain Kinase / Q000378:metabolism*; D043263:Myosin-Light-Chain Phosphatase / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D054460:rho-Associated Kinases
D000199:Actins; D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D017346:Protein Serine-Threonine Kinases; D054460:rho-Associated Kinases; D009219:Myosin-Light-Chain Kinase; D043263:Myosin-Light-Chain Phosphatase