Clinical application and study for signal transduction of human LH-receptor

人LH受体属于G蛋白偶联受体家族。黄体生成素受体在性腺中表达，在男性和女性生殖生理中都起着关键作用。在细胞水平上，性腺靶细胞上LH与LH- r结合引起Gs的刺激，进而激活腺苷酸环化酶，导致细胞内cAMP浓度增加。在我们最近的实验中，LH-R （L457R）突变体在完整的细胞和分离的细胞膜上既具有组成活性，又对进一步的激素刺激无反应。当以亚最大浓度共表达时，L457R不降低细胞表面LH-R的表达。然而，L457R的共表达导致LH-R诱导的cAMP产生的衰减。我们发现这种衰减是由磷酸二酯酶（PDE） 4D3的激活引起的。

The human LH receptor belongs to the family of G protein-coupled receptor. The LH receptor is expressed in the gonad, where it plays a pivotal role in both male and female reproductive physiology. On a cellular level, the binding of LH to the LH-R on gonadal target cells causes the stimulation of Gs, which in turn activates adenylyl cyclase, resulting in increased intracellular concentrations of cAMP.In our recent experiment, the LH-R (L457R) mutant was both constitutively active and unresponsive to further hormonal stimulation as determined on both intact cells and isolated membranes. When coexpressed at submaximal concentrations, L457R does not decrease the cell surface expression of LH-R. Coexpression of L457R, however, causes an attenuation of LH-stimulated cAMP production by LH-R. We found that this attenuation was caused by an activation of the phosphodiesterase (PDE) 4D3.