WASP family members and formin proteins coordinate regulation of cell protrusions in carcinoma cells.
We examined the role of the actin nucleation promoters neural Wiskott-Aldrich syndrome protein (N-WASP) and WAVE2 in cell protrusion in response to epidermal growth factor (EGF), a key regulator in carcinoma cell invasion. We found that WAVE2 knockdown (KD) suppresses lamellipod formation and increases filopod formation, whereas N-WASP KD has no effect. However, simultaneous KD of both proteins results in the formation of large jagged protrusions with lamellar properties and increased filopod formation. This suggests that another actin nucleation activity is at work in carcinoma cells in response to EGF. A mammalian Diaphanous-related formin, mDia1, localizes at the jagged protrusions in double KD cells. Constitutively active mDia1 recapitulated the phenotype, whereas inhibition of mDia1 blocked the formation of these protrusions. Increased RhoA activity, which stimulates mDia1 nucleation, was observed in the N-WASP/WAVE2 KD cells and was shown to be required for the N-WASP/WAVE2 KD phenotype. These data show that coordinate regulation between the WASP family and mDia proteins controls the balance between lamellar and lamellipodial protrusion activity.
Sarmiento
Corina
C
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA. csarmien@aecom.yu.edu
Wang
Weigang
W
Dovas
Athanassios
A
Yamaguchi
Hideki
H
Sidani
Mazen
M
El-Sibai
Mirvat
M
Desmarais
Vera
V
Holman
Holly A
HA
Kitchen
Susan
S
Backer
Jonathan M
JM
Alberts
Art
A
Condeelis
John
J
D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D002277:Carcinoma / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D022081:Cell Surface Extensions / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D042966:Cytochrome-B(5) Reductase / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation / Q000502:physiology; D004815:Epidermal Growth Factor / Q000378:metabolism / Q000494:pharmacology; D000080865:Formins; D009361:Neoplasm Invasiveness / Q000503:physiopathology; D009369:Neoplasms / Q000378:metabolism*; D011554:Pseudopodia / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D051300:Wiskott-Aldrich Syndrome Protein Family / Q000235:genetics / Q000378:metabolism*; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000235:genetics / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D002352:Carrier Proteins; C491464:Diap1 protein, mouse; D000080865:Formins; C495770:Wasl protein, rat; D051300:Wiskott-Aldrich Syndrome Protein Family; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D004815:Epidermal Growth Factor; C528412:Cyb5R3 protein, rat; D042966:Cytochrome-B(5) Reductase; D020742:rhoA GTP-Binding Protein