Phosphatidic acid-dependent recruitment and function of the Rac activator DOCK1 during dorsal ruffle formation.
Activation of receptor tyrosine kinases leads to the formation of two different types of plasma membrane structures: peripheral ruffles and dorsal ruffles. Although the formation of both ruffle types requires activation of the small GTPase Rac, the difference in kinetics suggests that a distinct regulatory mechanism operates for their ruffle formation. DOCK1 and DOCK5 are atypical Rac activators and are both expressed in mouse embryonic fibroblasts (MEFs). We found that although PDGF-induced Rac activation and peripheral ruffle formation were coordinately regulated by DOCK1 and DOCK5 in MEFs, DOCK1 deficiency alone impaired dorsal ruffle formation in MEFs. Unlike DOCK5, DOCK1 bound to phosphatidic acid (PA) through the C-terminal polybasic amino acid cluster and was localized to dorsal ruffles. When this interaction was blocked, PDGF-induced dorsal ruffle formation was severely impaired. In addition, we show that phospholipase D, an enzyme that catalyzes PA synthesis, is required for PDGF-induced dorsal, but not peripheral, ruffle formation. These results indicate that the phospholipase D-PA axis selectively controls dorsal ruffle formation by regulating DOCK1 localization.
Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan; Research Center for Advanced Immunology, Kyushu University, Fukuoka 812-8582, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Tokyo 102-0075, Japan.
Fumiyuki
F
Sanematsu
Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan; Research Center for Advanced Immunology, Kyushu University, Fukuoka 812-8582, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Tokyo 102-0075, Japan.
Akihiko
A
Nishikimi
Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Tokyo 102-0075, Japan.
Mayuki
M
Watanabe
Graduate School of Comprehensive Human Sciences, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki 305-8575, Japan.
Tsunaki
T
Hongu
Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan; Research Center for Advanced Immunology, Kyushu University, Fukuoka 812-8582, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Tokyo 102-0075, Japan.
Yoshihiko
Y
Tanaka
Graduate School of Comprehensive Human Sciences, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki 305-8575, Japan.
Yasunori
Y
Kanaho
Institut de Recherches Cliniques de Montréal, Université de Montréal, Montréal, Québec H2W 1R7, Canada.
Jean-François
JF
Côté
Division of Immunogenetics, Department of Immunobiology and Neuroscience, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan; Research Center for Advanced Immunology, Kyushu University, Fukuoka 812-8582, Japan; Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Tokyo 102-0075, Japan. Electronic address: fukui@bioreg.kyushu-u.ac.jp.
Yoshinori
Y
Fukui
D000595:Amino Acid Sequence; D000818:Animals; D021961:Cell Membrane Structures / Q000378:metabolism*; D002478:Cells, Cultured; D017124:Conserved Sequence; D004789:Enzyme Activation; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008822:Mice, Transgenic; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D010712:Phosphatidic Acids / Q000378:metabolism / Q000502:physiology*; D010739:Phospholipase D / Q000378:metabolism; D010982:Platelet-Derived Growth Factor / Q000502:physiology; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D015398:Signal Transduction; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology
C581047:DOCK1 protein, mouse; C531318:Dock5 protein, mouse; D020662:Guanine Nucleotide Exchange Factors; D010712:Phosphatidic Acids; D010982:Platelet-Derived Growth Factor; D011505:Protein-Tyrosine Kinases; D010739:Phospholipase D; D020744:rac GTP-Binding Proteins