Rac1-dependent lamellipodial motility in prostate cancer PC-3 cells revealed by optogenetic control of Rac1 activity.
The lamellipodium, an essential structure for cell migration, plays an important role in the invasion and metastasis of cancer cells. Although Rac1 recognized as a key player in the formation of lamellipodia, the molecular mechanisms underlying lamellipodial motility are not fully understood. Optogenetic technology enabled us to spatiotemporally control the activity of photoactivatable Rac1 (PA-Rac1) in living cells. Using this system, we revealed the role of phosphatidylinositol 3-kinase (PI3K) in Rac1-dependent lamellipodial motility in PC-3 prostate cancer cells. Through local blue laser irradiation of PA-Rac1-expressing cells, lamellipodial motility was reversibly induced. First, outward extension of a lamellipodium parallel to the substratum was observed. The extended lamellipodium then showed ruffling activity at the periphery. Notably, PI(3,4,5)P3 and WAVE2 were localized in the extending lamellipodium in a PI3K-dependent manner. We confirmed that the inhibition of PI3K activity greatly suppressed lamellipodial extension, while the ruffling activity was less affected. These results suggest that Rac1-induced lamellipodial motility consists of two distinct activities, PI3K-dependent outward extension and PI3K-independent ruffling.
Department of Urology, School of Medicine, Kagawa University, Miki, Kagawa, Japan.
Takuma
T
Kato
Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Kagawa, Japan.
Katsuhisa
K
Kawai
Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Kagawa, Japan.
Youhei
Y
Egami
Department of Urology, School of Medicine, Kagawa University, Miki, Kagawa, Japan.
Yoshiyuki
Y
Kakehi
Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Kagawa, Japan.
Nobukazu
N
Araki
D045744:Cell Line, Tumor; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D008297:Male; D009068:Movement; D062308:Optogenetics; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011471:Prostatic Neoplasms / Q000473:pathology*; D021381:Protein Transport; D011554:Pseudopodia / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
D004791:Enzyme Inhibitors; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D020830:rac1 GTP-Binding Protein