Department of Life Sciences, The Research Center for Cellular Homeostasis, Ewha Womans University, Seoul 120-750, Republic of Korea.
Skin QC Institute of Dermatological Sciences, Seoul, 03759, Republic of Korea.
Cell Signal. 2018 Dec;52:121-126. doi: 10.1016/j.cellsig.2018.09.003. Epub 2018 Sep 6.
Cell surface receptors must specifically recognize an extracellular ligand and then trigger an appropriate response within the cell. Their general structure enables this, as it comprises an extracellular domain that can bind an extracellular ligand, a cytoplasmic domain that can transduce a signal inside the cell to produce an appropriate response, and a transmembrane domain that links the two and is responsible for accurately delivering specific information on a binding event from the extracellular domain to the cytoplasmic domain, to trigger the proper response. A vast body of research has focused on elucidating the specific mechanisms responsible for regulating extracellular binding events and the subsequent interactions of the cytoplasmic domain with intracellular signaling. In contrast, far less work has focused on examining how the transmembrane domain links these domains and delivers the necessary information. In this review, we propose the importance of the transmembrane domain as a signal regulator. We highlight the cell adhesion receptor, syndecan, as a special case, and propose that the transmembrane domain-mediated oligomerization of the syndecan cytoplasmic domain is a unique regulatory mechanism in syndecan signaling.
细胞表面受体必须特异性识别细胞外配体，然后在细胞内引发适当的反应。其一般结构使其能够实现这一点，因为它包括一个可以结合细胞外配体的细胞外结构域、一个可以在细胞内转导信号以产生适当反应的细胞质结构域，以及一个将两者连接起来并负责将细胞外结构域上的绑定事件的特定信息准确传递到细胞质结构域以触发适当反应的跨膜结构域。大量研究集中于阐明负责调节细胞外结合事件的特定机制以及细胞质结构域与细胞内信号的后续相互作用。相比之下，很少有研究集中于检查跨膜结构域如何连接这些结构域并传递必要的信息。在这篇综述中，我们提出了跨膜结构域作为信号调节剂的重要性。我们强调了细胞黏附受体 syndecan 作为一个特殊情况，并提出跨膜结构域介导的 syndecan 细胞质结构域寡聚化是 syndecan 信号转导中的一种独特调节机制。
