Epidermal growth factor and phorbol esters reduce the levels of the cognate mRNA for the LH/CG receptor.
The LH/CG receptor of MA-10 Leydig tumor cells can be down-regulated by LH/CG, mouse epidermal growth factor (mEGF), cAMP analogues and phorbol esters. In a recent publication we showed that the LH/CG-induced down regulation of the LH/CG receptor is primarily due to an increase in the rate of degradation of the receptor, and occurs with little or no change in the levels of LH/CG receptor mRNA. Although relatively unimportant for the LH/CG-induced down-regulation of the LH/CG receptor, we also found that LH/CG can in fact elicit a reduction in LH/CG receptor mRNA and that this reduction is mediated by cAMP. These findings raised the possibility that the ability of other compounds to down-regulate the LH/CG receptor may be accompanied by decreases in LH/CG receptor mRNA. In an attempt to answer this question, we examined the possibility that the mEGF- or phorbol ester-induced down regulation of the LH/CG receptor is due to changes in LH/CG receptor mRNA. The experiments presented herein show that this is indeed the case.
Wang
H
H
Department of Physiology, University of Iowa College of Medicine, Iowa City 52242-1109.
Segaloff
D L
DL
Ascoli
M
M
D000818:Animals; D006063:Chorionic Gonadotropin / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D006801:Humans; D007985:Leydig Cells / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism*; D011974:Receptors, LH / Q000235:genetics*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013997:Time Factors; D014407:Tumor Cells, Cultured
D006063:Chorionic Gonadotropin; D012333:RNA, Messenger; D011974:Receptors, LH; D004815:Epidermal Growth Factor; D013755:Tetradecanoylphorbol Acetate