Feedback regulation between plasma membrane tension and membrane-bending proteins organizes cell polarity during leading edge formation.
Tension applied to the plasma membrane (PM) is a global mechanical parameter involved in cell migration. However, how membrane tension regulates actin assembly is unknown. Here, we demonstrate that FBP17, a membrane-bending protein and an activator of WASP/N-WASP-dependent actin nucleation, is a PM tension sensor involved in leading edge formation. In migrating cells, FBP17 localizes to short membrane invaginations at the leading edge, while diminishing from the cell rear in response to PM tension increase. Conversely, following reduced PM tension, FBP17 dots randomly distribute throughout the cell, correlating with loss of polarized actin assembly on PM tension reduction. Actin protrusive force is required for the polarized accumulation, indicating a role for FBP17-mediated activation of WASP/N-WASP in PM tension generation. In vitro experiments show that FBP17 membrane-bending activity depends on liposomal membrane tension. Thus, FBP17 is the local activator of actin polymerization that is inhibited by PM tension in the feedback loop that regulates cell migration.
Biosignal Research Center, Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
Kazuya
K
Tsujita
Department of Biochemistry and Molecular Biology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe, Hyogo 650-0017, Japan.
Tadaomi
T
Takenawa
Biosignal Research Center, Organization of Advanced Science and Technology, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, Hyogo 657-8501, Japan.
Toshiki
T
Itoh
D016475:3T3 Cells; D000199:Actins / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D016764:Cell Polarity / Q000502:physiology*; D002522:Chlorocebus aethiops; D004789:Enzyme Activation; D050556:Fatty Acid-Binding Proteins; D006801:Humans; D008081:Liposomes / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D015778:Minor Histocompatibility Antigens; D034622:RNA Interference; D034741:RNA, Small Interfering; D013314:Stress, Mechanical; D013312:Stress, Physiological; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal / Q000378:metabolism
D000199:Actins; D002352:Carrier Proteins; C433770:FNBP1 protein, human; C482527:FNBP1L protein, human; D050556:Fatty Acid-Binding Proteins; D008081:Liposomes; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; D015778:Minor Histocompatibility Antigens; D034741:RNA, Small Interfering; C406285:TRIP10 protein, human; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal