WAVE3-mediated cell migration and lamellipodia formation are regulated downstream of phosphatidylinositol 3-kinase.
WAVE3 is a member of the WASP/WAVE family of protein effectors of actin reorganization and cell movement. The precise role of WAVE3 in cell migration and its regulation, however, have not been elucidated. Here we show that endogenous WAVE3 was found to be concentrated in the lamellipodia at the leading edge of migrating MDA-MB-231 cells. Platelet-derived growth factor (PDGF) treatment induced lamellipodia formation as well as two-dimensional migration of cells in the wound-closure assay and chemotactic migration toward PDGF in three-dimensional migration chambers. Knockdown of WAVE3 expression by RNA interference prevented the PDGF-induced lamellipodia formation and cell migration. Treatment of cells with LY294002, an inhibitor of phosphatidylinositol 3-kinase (PI3K), also abrogated the PDGF-induced lamellipodia formation and cell migration, suggesting that PI3K may be required for WAVE3 activity. WAVE3 and the PI3K regulatory subunit, p85, were found to interact in a yeast two-hybrid screen, which was confirmed through co-immunoprecipitation. The WAVE3-p85 interaction was mediated by the N-terminal region of WAVE3 and the C-terminal SH2 domain of p85. These results imply that the WAVE3-mediated migration in MDA-MB-231 cells via lamellipodia formation is activated downstream of PI3K and induced by PDGF. The findings of the WAVE3-p85 partnership also suggest a potential regulatory role for p85 in WAVE3-dependent actin-cytoskeleton reorganization and cell migration.
Sossey-Alaoui
Khalid
K
Department of Cancer Genetics, Roswell Park Cancer Institute, Elm & Carlton Streets, Buffalo, NY 14263, USA. Khalid.Sossey-Alaoui@RoswellPark.org
Li
Xiurong
X
Ranalli
Tamara A
TA
Cowell
John K
JK
D000199:Actins / Q000737:chemistry; D045744:Cell Line, Tumor; D002465:Cell Movement; D002633:Chemotaxis; D002867:Chromones / Q000494:pharmacology; D003599:Cytoskeleton / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D008840:Microfilament Proteins / Q000378:metabolism / Q000502:physiology*; D008856:Microscopy, Fluorescence; D009025:Morpholines / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011554:Pseudopodia / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014162:Transfection; D020798:Two-Hybrid System Techniques; D051300:Wiskott-Aldrich Syndrome Protein Family; D014945:Wound Healing; D018909:src Homology Domains
D000199:Actins; D002867:Chromones; D004791:Enzyme Inhibitors; D008840:Microfilament Proteins; D009025:Morpholines; D010982:Platelet-Derived Growth Factor; D034741:RNA, Small Interfering; C120153:WASF3 protein, human; D051300:Wiskott-Aldrich Syndrome Protein Family; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D019869:Phosphatidylinositol 3-Kinases