Transforming growth factor β (TGF-β) plays an important role in normal development and homeostasis. Dysregulation of TGF-β responsiveness and its downstream signaling pathways contribute to many diseases, including cancer initiation, progression, and metastasis. TGF-β ligands bind to three isoforms of the TGF-β receptor (TGFBR) with different affinities. TGFBR1 and 2 are both serine/threonine and tyrosine kinases, but TGFBR3 does not have any kinase activity. They are necessary for activating canonical or noncanonical signaling pathways, as well as for regulating the activation of other signaling pathways. Another prominent feature of TGF-β signaling is its context-dependent effects, temporally and spatially. The diverse effects and context dependency are either achieved by fine-tuning the downstream components or by regulating the expressions and activities of the ligands or receptors. Focusing on the receptors in events in and beyond TGF-β signaling, we review the membrane trafficking of TGFBRs, the kinase activity of TGFBR1 and 2, the direct interactions between TGFBR2 and other receptors, and the novel roles of TGFBR3.

转化生长因子β（TGF-β）在正常发育和体内平衡中起着重要作用。TGF-β反应性及其下游信号通路的失调导致许多疾病，包括癌症的发生，发展和转移。TGF-β配体以不同的亲和力与TGF-β受体（TGFBR）的三种同工型结合。TGFBR1和2都是丝氨酸/苏氨酸和酪氨酸激酶，但是TGFBR3没有任何激酶活性。它们对于激活规范性或非规范性信号通路以及调节其他信号通路的激活都是必需的。TGF-β信号转导的另一个突出特征是其在时间和空间上的上下文相关效应。通过微调下游成分或调节配体或受体的表达和活性，可以实现多种效果和上下文相关性。着眼于TGF-β信号传导内外的事件中的受体，我们回顾了TGFBR的膜运输，TGFBR1和2的激酶活性，TGFBR2与其他受体之间的直接相互作用以及TGFBR3的新作用。