Biological function of the LH receptor is associated with slow receptor rotational diffusion.
Biological function of the LH receptor is associated with slow receptor rotational diffusion.
复制标题
LH 受体的生物学功能与缓慢的受体旋转扩散有关。
DOI：
10.1016/s0005-2736(00)00159-0
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Barisas,BG
中科院分区：
文献类型：
--
作者：
Roess,DA;Brady,CJ;Barisas,BG
The biological activity of luteinizing hormone (LH) receptors can be affected by modifications to the receptor’s amino acid sequence or by binding of hormone antagonists such as deglycosylated hCG. Here we have compared rotational diffusion of LH receptors capable of activating adenylate cyclase with that of non-functional hormone-occupied receptors at 4°C and 37°C using time-resolved phosphorescence anisotropy techniques. Binding of hCG to the rat wild-type receptor expressed on 293 cells (LHR-wt cells) or to the LH receptor on MA-10 cells produces functional receptors which exhibit rotational correlation times longer than 1000 μs. However, modification of the LH receptor by substitution of Lys583→Arg (LHR-K583R) results in a receptor that is non-functional and which has a significantly shorter rotational correlation time of 130±12 μs following binding of hCG. When these receptors are treated with deglycosylated hCG, an inactive form of hCG, the rotational correlation times for the LH receptors on LHR-wt and MA-10 cells are also shorter, namely 64±8 and 76±14 μs, respectively. Finally, a biologically active truncated form of the rat LH receptor expressed in 293 cells (LHR-t631) has slow rotational diffusion, greater than 1000 μs, when occupied by hCG and a significantly shorter rotational correlation time of 103±12 μs when occupied by deglycosylated hCG. The effects of rat LH binding to LH receptors on these various cell lines were similar to those of hCG although the magnitude of the changes in receptor rotational diffusion were less pronounced. We suggest that functional LH receptors are present in membrane complexes that exhibit slow rotational diffusion or are rotationally immobile. Shorter rotational correlation times for non-functional hormone–receptor complexes may reflect the absence of essential interactions between these complexes and other membrane proteins.
