title: Imaging sites of N-wasp activity in lamellipodia and invadopodia of carcinoma cells.
abstract: Cell migration is crucial for many biological and pathological processes such as chemotaxis of immune cells, fibroblast migration during wound healing, and tumor cell invasion and metastasis. Cells migrate forward by extending membrane protrusions. The formation of these protrusions is driven by assembly of actin filaments at the leading edge. Neural Wiskott-Aldrich syndrome protein (N-WASP), a ubiquitous member of the WASP family, induces actin polymerization by activating Arp2/3 complex and is thought to regulate the formation of membrane protrusions. However, it is totally unclear how N-WASP activity is spatially and temporally regulated inside migrating cells. To detect and image sites of N-WASP activity during cell motility and invasion in carcinoma cells, we designed an N-WASP fluorescence resonance energy transfer (FRET) biosensor that distinguishes between the active and inactive conformations and mimics the function of endogenous N-WASP. Our data show that N-WASP is involved in lamellipodia extension, where it is activated at the leading edge, as well as in invadopodia formation of invasive carcinoma cells, where it is activated at the base. This is the first time that the activity of full-length N-WASP has been visualized in vivo, and this has lead to new insights for N-WASP function.
authors.affiliation: Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA. mlorenz@aecom.yu.edu
authors.forename: Mike
authors.initials: M
authors.lastname: Lorenz
authors.forename: Hideki
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Yarong
authors.initials: Y
authors.lastname: Wang
authors.forename: Robert H
authors.initials: RH
authors.lastname: Singer
authors.forename: John
authors.initials: J
authors.lastname: Condeelis
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D002465:Cell Movement / Q000502:physiology*; D004815:Epidermal Growth Factor; D031541:Fluorescence Resonance Energy Transfer; D015151:Immunoblotting; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000502:physiology; D011554:Pseudopodia / Q000378:metabolism*; D051381:Rats; D014407:Tumor Cells, Cultured; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal
chemical_list: D009419:Nerve Tissue Proteins; C495770:Wasl protein, rat; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; D004815:Epidermal Growth Factor