Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA.
Immunol Rev. 2009 Nov;232(1):72-83. doi: 10.1111/j.1600-065X.2009.00828.x.
Transmembrane adapter proteins (TRAPs) are critical components of signaling pathways in lymphocytes, linking antigen receptor engagement to downstream cellular processes. While these proteins lack intrinsic enzymatic activity, their phosphorylation following receptor ligation allows them to function as scaffolds for the assembly of multi-molecular signaling complexes. Many TRAPs have recently been discovered, and numerous studies demonstrate their roles in the positive and negative regulation of lymphocyte maturation, activation, and differentiation. One such example is the linker for activation of T cells (LAT) family of adapter proteins. While LAT has been shown to play an indispensable role in T-cell and mast cell function, the other family members, linker for activation of B cells (LAB) and linker for activation of X cells (LAX), are necessary to fine-tune immune responses. In addition to its well-established role in the positive regulation of lymphocyte activation, LAT exerts an inhibitory effect on T-cell receptor-mediated signaling. Furthermore, LAT, along with LAB and LAX, plays a crucial role in establishing and maintaining tolerance. Here, we review recent data concerning the regulation of lymphocyte development and activation by the LAT family of proteins.
跨膜衔接蛋白（TRAPs）是淋巴细胞信号通路的关键组成部分，将抗原受体的结合与下游细胞过程联系起来。虽然这些蛋白缺乏内在的酶活性，但它们在受体结合后发生的磷酸化使其能够作为多分子信号复合物组装的支架。最近发现了许多 TRAPs，许多研究表明它们在淋巴细胞成熟、激活和分化的正调控和负调控中发挥作用。其中一个例子是 T 细胞激活衔接蛋白（LAT）家族的衔接蛋白。虽然已经证明 LAT 在 T 细胞和肥大细胞功能中发挥不可或缺的作用，但其他家族成员，B 细胞激活衔接蛋白（LAB）和 X 细胞激活衔接蛋白（LAX），对于精细调节免疫反应是必需的。除了其在淋巴细胞激活的正调控中的既定作用外，LAT 对 T 细胞受体介导的信号传递也有抑制作用。此外，LAT 与 LAB 和 LAX 一起，在建立和维持耐受方面发挥着关键作用。在这里，我们回顾了有关 LAT 家族蛋白对淋巴细胞发育和激活的调控的最新数据。
