title: Rap1 and integrin inside-out signaling.
abstract: In leukocytes, integrins play important roles in adhesive interactions with endothelium, antigen-presenting cells, and effector functions such as cytotoxicity. This chapter describes methods to study Ras proximity 1 (Rap1), a signaling molecule that has been increasingly recognized as an important regulator of integrin-mediated cell adhesion in the immune system as well as hemostasis. Rap1 is activated by a wide variety of external stimuli including chemokines and antigens. Signaling via Rap1 transmits an inside-out signal to the integrins, thereby increasing adhesiveness to ligands such as immunoglobulin superfamily proteins as well as extracellular matrix proteins and plasma proteins. This process induces leukocyte cell adhesion to the endothelium and antigen-presenting cells. In addition to integrin regulation, activated Rap1 induces cell polarity of lymphocytes, which is coordinated with LFA-1 redistribution to the leading edge.
authors: Department of Life Science, School of Science and Technology, Kansei Gakuin University, Hyogo, Japan. kinashi@takii.kmu.ac.jp
authors: Koko
authors: K
authors: Katagiri
authors: Tatsuo
authors: T
authors: Kinashi
mesh_terms: D000818:Animals; D000938:Antigen-Presenting Cells / Q000378:metabolism; D002448:Cell Adhesion / Q000276:immunology; D002460:Cell Line; D018925:Chemokines / Q000494:pharmacology; D004789:Enzyme Activation; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D019169:Jurkat Cells; D016169:Lymphocyte Function-Associated Antigen-1 / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D011485:Protein Binding; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D015398:Signal Transduction; D020827:rap1 GTP-Binding Proteins / Q000378:metabolism*
chemical_list: D018925:Chemokines; D016023:Integrins; D016169:Lymphocyte Function-Associated Antigen-1; D011948:Receptors, Antigen, T-Cell; D020827:rap1 GTP-Binding Proteins