Katagiri Koko, Kinashi Tatsuo
Department of Life Science, School of Science and Technology, Kansei Gakuin University, Hyogo, Japan.
Methods Mol Biol. 2012;757:279-96. doi: 10.1007/978-1-61779-166-6_18.
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.
在白细胞中，整合素在与内皮细胞、抗原呈递细胞的黏附相互作用以及细胞毒性等效应功能中发挥重要作用。本章介绍了研究Ras相关蛋白1（Rap1）的方法，Rap1是一种信号分子，在免疫系统以及止血过程中，它作为整合素介导的细胞黏附的重要调节因子，越来越受到认可。Rap1可被多种外部刺激激活，包括趋化因子和抗原。通过Rap1的信号传导将由内向外的信号传递给整合素，从而增加对免疫球蛋白超家族蛋白、细胞外基质蛋白和血浆蛋白等配体的黏附性。这一过程诱导白细胞与内皮细胞和抗原呈递细胞的黏附。除了整合素调节外，活化的Rap1还诱导淋巴细胞的细胞极性，这与淋巴细胞功能相关抗原-1（LFA-1）重新分布到前沿区域相协调。
