CLP36 and RIL recruit α-actinin-1 to stress fibers and differentially regulate stress fiber dynamics in F2408 fibroblasts.
CLP36 is a member of the ALP/Enigma protein family and has been shown to be localized to stress fibers in various cells. We previously reported that depletion of CLP36 caused loss of stress fibers in BeWo choriocarcinoma cells, but it remains unclear how CLP36 contributes to stress fiber formation. In this study, we generated CLP36-depleted F2408 fibroblasts and found that stress fibers showed abnormal non-oriented organization in these cells. In addition to CLP36, F2408 cells contained RIL, another ALP/Enigma protein, and we demonstrated that RIL could compensate for the role of CLP36 in stress fiber formation. CLP36 and RIL form a complex with α-actinin-1 and palladin. We found a strong correlation between loss of CLP36/RIL and failure of α-actinin-1 or palladin to localize on stress fibers. In addition, time lapse observation revealed that incorporation of RIL stabilizes stress fibers and that CLP36 influences the dynamic architecture of these fibers. Our findings indicate that CLP36 and RIL have a redundant role in the formation of stress fibers, but have different effects on stress fiber dynamics in F2408 cells.
Department of Anatomy, Hamamatsu University School of Medicine, 431-3192 Shizuoka, Japan. k.miya@hama-med.ac.jp
Kazufumi
K
Miyazaki
Koji
K
Ohno
Naoaki
N
Tamura
Takeshi
T
Sasaki
Kohji
K
Sato
D000185:Actinin / Q000378:metabolism*; D000818:Animals; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism*; D060588:LIM Domain Proteins / Q000378:metabolism*; D051381:Rats; D022502:Stress Fibers / Q000378:metabolism*
D004268:DNA-Binding Proteins; D060588:LIM Domain Proteins; C097168:Pdlim1 protein, rat; C091504:Pdlim4 protein, rat; D000185:Actinin