Fascin, an actin-bundling protein, induces membrane protrusions and increases cell motility of epithelial cells.
Fascin is an actin-bundling protein that is found in membrane ruffles, microspikes, and stress fibers. The expression of fascin is greatly increased in many transformed cells, as well as in specialized normal cells including neuronal cells and antigen-presenting dendritic cells. A morphological characteristic common to these cells expressing high levels of fascin is the development of many membrane protrusions in which fascin is predominantly present. To examine whether fascin contributes to the alterations in microfilament organization at the cell periphery, we have expressed fascin in LLC-PK1 epithelial cells to levels as high as those found in transformed cells and in specialized normal cells. Expression of fascin results in large changes in morphology, the actin cytoskeleton, and cell motility: fascin-transfected cells form an increased number of longer and thicker microvilli on apical surfaces, extend lamellipodia-like structures at basolateral surfaces, and show disorganization of cell-cell contacts. Cell migration activity is increased by 8-17 times when assayed by modified Boyden chamber. Microinjection of a fascin protein into LLC-PK1 cells causes similar morphological alterations including the induction of lamellipodia at basolateral surfaces and formation of an increased number of microvilli on apical surfaces. Furthermore, microinjection of fascin into REF-52 cells, normal fibroblasts, induces the formation of many lamellipodia at all regions of cell periphery. These results together suggest that fascin is directly responsible for membrane protrusions through reorganization of the microfilament cytoskeleton at the cell periphery.
Yamashiro
S
S
Department of Molecular Biology and Biochemistry, Rutgers University, Busch Campus, Piscataway, New Jersey 08855, USA.
Yamakita
Y
Y
Ono
S
S
Matsumura
F
F
D008841:Actin Cytoskeleton / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D002461:Cell Line, Transformed; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure; D002465:Cell Movement / Q000502:physiology*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D003599:Cytoskeleton / Q000648:ultrastructure; D004847:Epithelial Cells / Q000502:physiology / Q000648:ultrastructure; D015870:Gene Expression; D006367:HeLa Cells; D006801:Humans; D018374:LLC-PK1 Cells; D008840:Microfilament Proteins / Q000235:genetics / Q000502:physiology*; D008845:Microinjections; D051381:Rats; D013552:Swine; D015534:Trans-Activators; D014162:Transfection; D014170:Transformation, Genetic; D016596:Vinculin / Q000032:analysis; D051176:beta Catenin
D000199:Actins; C495270:CTNNB1 protein, human; D002352:Carrier Proteins; C495268:Ctnnb1 protein, rat; D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins; D015534:Trans-Activators; D051176:beta Catenin; D016596:Vinculin; C020324:fascin