Protein kinase Cα/β inhibitor Gö6976 promotes PC12 cell adhesion and spreading through membrane recruitment and activation of protein kinase Cδ.
Gö6976 is a nonglycosidic indolocarbazole compound widely used as a specific inhibitor of PKCα/β. In experiments probing for a role of PKCα in human laminin-2-integrin-mediated cell adhesion and spreading of PC12 cells, we observed unexpected enhancements of adhesion, spreading and stress fiber formation to 1 μM Gö6976 with concomitant increase in membrane translocation of PKCδ and autophosphorylation of focal adhesion kinase (FAK). Importantly, enhanced cellular behavior and membrane translocation of PKCδ induced by Gö6976 was retained in siRNA-transfected PC12 cells to knockdown PKCα expression. Gö6976 also induced laminin-dependent cell adhesion in NIH/3T3 and CV-1 fibroblasts, suggesting of a mechanism that may be common to multiple cell-types. A specific inhibitor of PKCδ, rottlerin, completely abrogated Gö6976-dependent increase in PC12 cell adhesion to laminin as well as the activation of small GTPases, Rac1 and Cdc42, that are downstream of PKCδ in adhesion receptor signaling. siRNA knockdown of Rac1 and Cdc42 expression inhibited cell spreading and lamellipodia formation in PC12 cells. Overall, these results suggest that Gö6976 may stimulate membrane recruitment of PKCδ through a mechanism that is independent of PKCα/β signaling. In addition, the activation of Rac1 and Cdc42 by human laminin-2-integrin-dependent activation of PKCδ/FAK signaling mediates cell spreading and lamellipodia formation in PC12 cells.
Department of Oral Biochemistry and Program in Cancer and Developmental Biology, Seoul National University School of Dentistry, Seoul, Republic of Korea.
Sung Youn
SY
Jung
O Bok
OB
Kim
Hyun Ki
HK
Kang
Da Hyun
DH
Jang
Byung-Moo
BM
Min
Frank H
FH
Yu
D000818:Animals; D002227:Carbazoles / Q000494:pharmacology*; D002448:Cell Adhesion / Q000187:drug effects; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D004789:Enzyme Activation / Q000187:drug effects; D057809:HEK293 Cells; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D016716:PC12 Cells; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D064546:Protein Kinase C beta; D051571:Protein Kinase C-alpha / Q000037:antagonists & inhibitors; D051745:Protein Kinase C-delta / Q000378:metabolism / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D015854:Up-Regulation / Q000187:drug effects
D002227:Carbazoles; D047428:Protein Kinase Inhibitors; C081021:Go 6976; D011493:Protein Kinase C; D064546:Protein Kinase C beta; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta