Wang X F, Lin H Y, Ng-Eaton E, Downward J, Lodish H F, Weinberg R A
Whitehead Institute for Biomedical Research, Cambridge, Massachusetts 02142.
Cell. 1991 Nov 15;67(4):797-805. doi: 10.1016/0092-8674(91)90074-9.
The rat TGF-beta type III receptor cDNA has been cloned by overexpression in COS cells. The encoded receptor is an 853 amino acid protein with a large N-terminal extracellular domain containing at least one site for glycosaminoglycan addition, a single hydrophobic transmembrane domain, and a 41 amino acid cytoplasmic tail with no obvious signaling motif. Introduction of the cDNA into COS cells and L6 myoblasts induces expression of a heterogenously glycosylated 280-330 kd protein characteristic of the type III receptor that binds TGF-beta 1 specifically. In L6 myoblasts lacking the endogenous type III receptor, expression of the recombinant receptor leads to an increase in the amount of ligand bound and cross-linked to surface type II TGF-beta receptors. This indicates that the type III receptor may regulate the ligand-binding ability or surface expression of the type II receptor.
大鼠转化生长因子βⅢ型受体cDNA已通过在COS细胞中的过表达进行克隆。编码的受体是一种853个氨基酸的蛋白质，具有一个大的N端细胞外结构域，其中至少有一个糖胺聚糖添加位点、一个单一的疏水跨膜结构域和一个41个氨基酸的细胞质尾巴，没有明显的信号基序。将该cDNA导入COS细胞和L6成肌细胞可诱导一种异质性糖基化的280 - 330kd蛋白质的表达，该蛋白质是Ⅲ型受体的特征，可特异性结合转化生长因子β1。在缺乏内源性Ⅲ型受体的L6成肌细胞中，重组受体的表达导致与表面Ⅱ型转化生长因子β受体结合并交联的配体量增加。这表明Ⅲ型受体可能调节Ⅱ型受体的配体结合能力或表面表达。
