High impact information on FSHR

• Purification of follitropin receptor from bovine calf testes [1].
• 5) After cholera toxin-induced [32P]ADP-ribosylation of testis membranes, a major peak of radioactivity (presumably Ns) was coeluted with FSH receptor activity from the Sepharose-6B column [2].
• Several lines of evidence suggest that 6B-Fraction-1 is a complex consisting of FSH receptor and a guanine nucleotide regulatory protein, probably Ns [2].
• Moreover, the N protein which mediates GTP regulation of FSH-receptor binding appears to be relatively insensitive to N-ethylmaleimide, unlike the N-ethylmaleimide sensitivity of the turkey erythrocyte Ns [3].
• The expression of mRNA for FSH receptor was highest in granulosa cells of dominant follicles collected on day 3 of the follicular wave (P < 0.05) and was not different between dominant and subordinate follicles on day 2 of the wave (P > 0.05) [4].

Biological context of FSHR

• We conclude that bovine cervix at the time of the peripheral plasma FSH peak (pre-estrus/estrus) contains high levels of FSHR and responds to FSH by increasing the PGE(2) production responsible for cervical relaxation at estrus [5].
• The PCR-RFLP analysis made it possible to identify the LHR and FSHR genotypes, as well as to characterize the degree of heterozygosis, which was high for all of the breed compositions, for both loci, except for two combinations for LHR (B and C) [6].
• Our results suggest that the bovine testis FSH receptor contains predominantly N-linked oligosaccharide chains consistent with recently predicted N-linked glycosylation sites of cloned FSH receptor of rat testis [7].
• The effectiveness of antibodies against FSH receptor in stimulating estradiol synthesis suggests that the information needed for FSH signal transduction resides in the membrane receptor rather than in the hormone molecule [8].
• Expression of follicle-stimulating hormone-receptor mRNA alternate transcripts in bovine granulosa cells during luteinization in vivo and in vitro [9].

Anatomical context of FSHR

• Distinct regulation by steroids of messenger RNAs for FSHR and CYP19A1 in bovine granulosa cells [10].
• The level of FSHR (75 kDa) was significantly higher (p < 0.01) in Western blots of pre-estrous/estrous cervix than in other cervical tissues [5].
• In addition, synchronized changes in the pattern of COC IGFBP-2 and FSHR expression during oocyte maturation suggest possible synergistic actions between IGF-1 and FSH [11].
• The objective of this study was to investigate changes in expression of mRNAs encoding FSH receptor (FSHr), LH receptor (LHr), cytochrome P450 side-chain cleavage (P450(scc)), cytochrome P450 17alpha-hydroxylase (P450(c17)), and cytochrome P450 aromatase (P450(arom)) during recruitment and selection of bovine ovarian follicles [12].
• For a better characterisation of classes the mRNA expressions of FSH receptor, LH receptor and aromatase cytochrome P450 in theca interna (TI) and granulosa cells (GC) were determined [13].

Associations of FSHR with chemical compounds

• FSHR mRNA was increased by T and DHT but not E2 [10].
• In contrast, DHT alone had no effect on CYP19A1 mRNA but synergized with FSH plus E2 to increase CYP19A1 mRNA, probably due to induction of FSHR by DHT [10].
• Similarly, varying treatment duration (1-5 days) showed that FSHR was increased by T and DHT and CYP19A1 mRNA increased by E2 and T at all times [10].
• However, the specific androgen receptor antagonist bicalutamide did not block E2 or T effects on CYP19A1 but did block T and DHT stimulation of FSHR [10].
• Differences in expression of mRNA for LH receptor, FSH receptor, cytochrome P450 side-chain cleavage, 3beta-hydroxysteroid dehydrogenase, cytochrome P450 17alpha-hydroxylase (P450c17) and cytochrome P450 aromatase were determined in large follicles using in situ hybridization [14].

Physical interactions of FSHR

• Aprotinin did not inhibit [3H]5'-guanylylimidodiphosphate binding to FSH receptor-enriched membranes, suggesting that its effects on the affinity of the receptor for FSH and on AC activation were not mediated through an interaction with FSH receptor-associated G-protein [15].
• Stabilization of follicle-stimulating hormone-receptor complexes may involve calcium-dependent transglutaminase activation [16].

Other interactions of FSHR

• In contrast, levels of IGFBP-2 and FSHR expression decreased (P < 0.05) in matured COC [11].
• Incubation of FSH (10 ng/ml) with pre-estrous/estrous cervix resulted in a 3-fold increase in the expression of FSHR and a 2-fold increase in both G protein (alpha(s)) and cyclooxygenase II [5].
• The rate of association of [125I]hFSH with its receptor was reduced by 50% in the presence of aprotinin, but no effect on dissociation of FSH-receptor complexes was evident [15].
• Our results indicate that recognition of FSH-beta by N-terminus region (9-30) of the FSH receptor involves contact with residues in three discontinuous binding regions on FSH-beta.(ABSTRACT TRUNCATED AT 250 WORDS)[17]
• One day after luteinization in vivo, full-length FSH-receptor mRNA was detectable at low levels in the newly-formed corpus luteum [9].

Analytical, diagnostic and therapeutic context of FSHR

• Methods: CHO-TSHR, CHO-LHR, and CHO-FSHR cells were incubated with bovine TSH (0.1-25mU/mL), human recombinant chorionic gonadotropin (hCG; 0.5-10mU/mL) or human recombinant FSH (100-5000mU/mL) or with M22 IgG (0.001-5.0 microg/mL), and the extracellular cyclic AMP was measured by radioimmunoassay [18].
• The immunoprecipitate, after dissociation of receptor from antibody, separation by SDS-PAGE under reducing conditions, and autoradiography, showed the presence of a approximately 60 kDa protein previously identified as a component of the FSH receptor [8].
• Using RT-PCR and Southern blotting, three alternate transcripts of the FSH-receptor were found consistently in bovine granulosa cells [9].
• Nucleotide sequence analysis and alignment of the cloned PCR products showed the presence of two isoforms of the FSH receptor mRNA and two isoforms of the LH receptor mRNA [19].
• This model system was utilized to study the effects of FSH on the quaternary structure of FSH receptor-associated GTP-binding protein by comparing the gel filtration profiles of proteoliposomes solubilized with Triton X-100 after exposure to [3H]Gpp(NH)p in the presence or absence of FSH [20].

References