整合素(integrin)是一类重要的细胞表面黏附分子,是由α和β两个亚基通过非共价键组成的异源二聚体,对于免疫反应、免疫细胞的组织定位、凝血、组织愈伤、癌细胞转移以及组织和器官的发育等都至关重要。整合素的功能依赖于对其配体结合的亲和性及其所介导的信号转导的动态调控,整合素活化受阻或是过度活化都会引发多种疾病。目前,对整合素的活化机制的了解比较深入,研究发现,整合素活化的最终步骤是由talin和kindlin等胞内调控蛋白结合β亚基胞内段引起的;但是对于调控整合素去活化的机制了解较少。该文重点介绍了负调控整合素活化的蛋白分子及相关分子机制。
Integrins are a family of α/β heterodimeric cell adhesion molecules, playing key roles in a number of important biological processes, such as immune responses, leukocyte trafficking, maintenance of tissue homeostasis and development. The function of integrins is dependent on the dynamic regulation of integrin affinity and its intracellular signaling. The abnormal integrin activation and deactivation are associated with many human diseases. Studies have revealed that the binding of intracellular proteins, such as talin and kindlin, to integrin cytoplasmic tail is a critical step for integrin activation. However, less is known about the mechanism of integrin deactivation. In this review, we aim to discuss the recent progresses in understanding the mechanisms underlying the integrin deactivation.