Filopodia: the fingers that do the walking.
Filopodia are actin-based structures composed of parallel bundles of actin filaments and various actin-associated proteins, and they play important roles in cell-cell signaling, guidance toward chemoattractants, and adhesion to the extracellular matrix. Two mechanisms for the formation of filopodia have been suggested, each using different sets of actin-regulating proteins, creating some controversy in the field. New molecules, some of unknown functions, have also been implicated in filopodium formation, suggesting that other possible mechanisms of filopodium formation exist. We discuss established and novel proteins that mediate the formation and dynamics of filopodia, different mechanisms of filopodium formation, and the various functions that distinct filopodia perform.
Gupton
Stephanie L
SL
Department of Biology, Center for Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. gupton@mit.edu
Gertler
Frank B
FB
D008841:Actin Cytoskeleton / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D003598:Cytoskeletal Proteins / Q000378:metabolism / Q000502:physiology; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism / Q000502:physiology*; D008954:Models, Biological; D011485:Protein Binding; D011554:Pseudopodia / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction
D003598:Cytoskeletal Proteins; D008840:Microfilament Proteins