Subunit interaction of human chorionic gonadotropin (hCG) with rat ovarian luteinizing hormone (LH)/CG receptor

Content Provider	Semantic Scholar
Author	Petäjä-Repo, Ulla E. Rajaniemi, Hannu
Copyright Year	1990
Abstract	The subunit interaction of hCG with its rat ovarian LH/CG receptor was studied by cross-linking the solubilized receptor-hormone complex with glutaraldehyde (GA), disuccinimidyl suberate (DSS) or dithiobis(succinimidyl propionate) (DSP) and analyzing the complexes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and autoradiography. The hormone was labeled either in its alpha-subunit (125I-hCG) or in its beta-subunit (3H-hCG) or the label (3H) was introduced into the receptor molecule instead of the hormone. All of the labeling procedures led to the detection of only the receptor-(alpha,beta)hCG and receptor-(alpha)hCG complexes on the autoradiograms. The sizes of these complexes were 137,000 and 106,000, respectively, under reducing conditions. These results suggest that the receptor binds one hormone molecule, and that hCG interacts with the receptor mainly through its alpha-subunit. In addition, polyclonal antibodies directed against the LH/CG receptor and the alpha- and beta-subunits of hCG were used to detect the non-reduced receptor-(alpha,beta)hCG complex in immunoblotting. As antibodies directed against both the alpha-subunit and the beta-subunit were able to detect the Mr 130,000 complex, it is conceivable that both of the subunits are at least partially exposed on the receptor-hormone complex. 125I-hCG was also cross-linked to the membrane-bound receptor. The membrane-bound complex had an Mr of 144,000 under reducing conditions, i.e. approximately 7000 higher than that of the solubilized complex (Mr 137,000). This may indicate that the membrane-bound receptor is covalently modified or differs in conformation from the solubilized receptor.
Starting Page	43
Ending Page	53
Page Count	11
File Format	PDF HTM / HTML
DOI	10.1016/0303-7207(90)90238-4
PubMed reference number	1703092
Journal	Medline
Volume Number	72
Alternate Webpage(s)	https://api.elsevier.com/content/article/pii/0303720790902384
Alternate Webpage(s)	https://www.sciencedirect.com/science/article/pii/0303720790902384?dgcid=api_sd_search-api-endpoint
Alternate Webpage(s)	https://doi.org/10.1016/0303-7207%2890%2990238-4
Journal	Molecular and Cellular Endocrinology
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article