Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Screening of a human genomic library with a cDNA probe corresponding to the transmembrane domain of the FSH receptor (FSHR) resulted in the identification of a positive clone with a DNA insert of approximately 17.5 kb. Part of the clone encoded exon 10 of the FSHR gene. Sequence analysis of this exon revealed an open reading frame corresponding to base positions 855-2085 of the FSHR cDNA, thereby coding for 410 amino acids. Exon 10 was found to comprise the seven transmembrane domains, the C-terminal intracellular domain and a fragment of 81 amino acids belonging to the extracellular N-terminal domain of the FSHR. The exon/intron boundary is in phase 2 and the amino acid which resides in this junction is isoleucine. The genomic clone was used to map the chromosomal localization of the human FSHR gene. In situ hybridization experiments allowed the allocation of the human gene to chromosome 2 p21. As this position is identical to that of the human LH receptor gene, these two receptor genes may have evolved from a common ancestor.
J Mol Endocrinol 1994 Jun
PMID:Localization of the human FSH receptor to chromosome 2 p21 using a genomic probe comprising exon 10. 791 67

The original 'two-cell mechanism' explained the endocrine regulation of follicular oestrogen synthesis and implied paracrine signalling in the follicle wall. It is now known that the CYP17 gene encoding 17-hydroxylase/C17-20-lyase activity crucial to androgen synthesis, is expressed exclusively in thecal cells. 17-Hydroxylase/C17-20-lyase activity is regulated by LH and subject to local modulation by a factor(s) emanating in FSH-stimulated granulosa cells. The FSH receptor gene is expressed exclusively in granulosa cells, where FSH acts directly to induce cytoproliferation and differentiation via cyclic AMP/protein kinase-A mediated post-receptor signalling. Granulosa cells also express androgen receptors, and theca-derived androgen has the potential to modulate locally differentiative responses to FSH. When follicles are recruited to preovulatory development by FSH, their granulosa cells develop LH receptors functionally coupled to aromatase activity and inhibin production. Thereby they simultaneously undertake LH-responsive aromatization and inhibin synthesis. Inhibin has the potential to potently enhance LH-stimulated thecal androgen synthesis. Granulosa-derived inhibin may therefore participate in a paracrine mechanism that locally amplifies androgen synthesis, and hence oestrogen formation, in the preovulatory follicle(s).
Mol Cell Endocrinol 1994 Apr
PMID:Follicular oestrogen synthesis: the 'two-cell, two-gonadotrophin' model revisited. 805 58

Follicle stimulating hormone (FSH) plays an important role in the regulation of oogenesis, spermatogenesis and production of steroid hormones. Receptors to FSH, which are uniquely expressed in ovarian granulosa and testicular Sertoli cells, are rapidly lost in tissue culture conditions and upon cell transformation. We have succeeded, by triple transfection of primary rat granulosa cells with SV40 DNA, Ha-ras oncogene and an FSH receptor expression plasmid, to establish stable steroidogenic cell lines expressing FSH receptors. The cell lines respond to rat, ovine and bovine FSH, which stimulate progesterone production at levels comparable to primary granulosa cells obtained from preovulatory follicles. No steroidogenic response is detected upon stimulation with ovine luteinizing hormone or human chorionic gonadotropin. The steroidogenic response is accompanied by de novo appearance of adrenodoxin which serves as a marker for the mitochondrial steroidogenic enzyme system. These cells express approximately 27,000 receptors per cell with a Kd of 100-115 pM. This Kd is close to the value calculated for the native receptor. The ED50 for the steroidogenic response to ovine FSH is 200 pM, suggesting a tight coupling between receptor activation and the steroidogenic response. FSH induces pronounced morphological changes in the established cell lines, which are also characteristic of primary granulosa cells. These FSH responsive cell lines can serve as a useful model for the study of the structure and function of the FSH receptor and the effect of oncogenes on its expression.
Mol Cell Endocrinol 1993 Sep
PMID:Establishment of steroidogenic granulosa cell lines expressing follicle stimulating hormone receptors. 824 96

We have recently identified a region, N-terminus residues 9-30, in the extracellular domain of the follicle-stimulating hormone (FSH) receptor capable of binding FSH, but not luteinizing hormone (LH) or thyroid-stimulating hormone (FSH) (Dattatreyamurty and Reichert (1992) Mol. Cell. Endocrinol. 87, 9-17). The objectives of the present study were to examine the interaction between a synthetic peptide corresponding to this receptor sequence and the beta-subunit of FSH, and to identify which FSH-beta regions are involved in the interaction. FSH-beta subunit and synthetic FSH-beta peptides 1-15, 71-85 and 101-111 effectively bound 125I-labeled FSH rec-(9-30) peptide, and binding was inhibited by excess unlabeled FSH receptors. Scatchard analysis indicated that the synthetic FSH-beta peptides had affinities for FSH rec-(9-30) peptide in the order of 10(6) M-1 (Ka), with the sum of individual peptide affinities (Ka = 1.21 x 10(7) M-1) closely approximating that of the intact beta-subunit (1.02 x 10(7) M-1). Polyclonal antibodies raised against FSH rec-(9-30) peptide completely inhibited the binding of 125I-labeled receptor peptide to hFSH, hFSH-beta, and hFSH-beta peptides 1-15, 71-85 and 101-111. 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)
Mol Cell Endocrinol 1993 May
PMID:Identification of regions of the follitropin (FSH) beta-subunit that interact with the N-terminus region (residues 9-30) of the FSH receptor. 831 32

The structure of RNA encoding the mouse testis FSH receptor was studied using reverse transcription and the polymerase chain reaction. Four major bands were observed by ethidium bromide staining and by hybridization to an FSH-receptor cDNA probe. The largest of these bands was the expected size (779 bp) while the other bands were spaced approximately 70 bp apart. Using alternative primers, each of the products was shown to contain exons 1, 9 and 10. Exons 2-8 in the FSH receptor gene are between 68 and 77 bp in size, suggesting that these multiple products arise by alternate splicing of the region encoding the extracellular domain of the receptor. A similar pattern of splicing was observed in cDNA from the testes of hypogonadal mice, showing that this alternative splicing pattern is not gonadotrophin-dependent.
J Mol Endocrinol 1993 Jun
PMID:Discrete splicing alternatives in mRNA encoding the extracellular domain of the testis FSH receptor in the normal and hypogonadal (hpg) mouse. 837 19

WT1, a gene deleted in some Wilms' tumors, encodes a transcription factor with zinc fingers and shares homology with proteins in the early growth response gene family. Although defects in the WT1 gene are associated with nephroblastoma and genitourinary malformation, the specific function of WT1 in the gonads remains unclear. We investigated the expression of WT1 transcripts in rat ovary during follicle development by Northern blotting, RNase protection assay, and in situ hybridization. Abundant WT1 transcripts were found in the ovary, testis, uterus, and kidney, with lower levels in the heart and pancreas. Treatment with estrogen or gonadotropins did not affect the concentration of ovarian WT1 mRNA. In situ hybridization analysis indicated that ovarian WT1 mRNA is expressed exclusively in the surface epithelium and granulosa cells of primordial, primary, and secondary follicles, and its levels decrease during follicle growth. Although RNase protection assay suggested the presence of four alternatively spliced forms of WT1 mRNA, the ratio of these transcripts remains constant during ovarian growth. Developmental changes in the expression of two granulosa cell differentiation marker genes, inhibin-alpha and FSH receptor, were found to be inversely correlated with WT1 levels. Because potential WT1-binding sites were found in the promoter of inhibin-alpha gene, we further tested whether WT1 might regulate the expression of this gene. Cotransfection of a WT1 expression vector with a promoter reporter plasmid of inhibin-alpha resulted in the repression of promoter activities in CHO cells in a dose-dependent manner. These results suggest that WT1 is expressed in high levels in granulosa cells of primordial, primary, and secondary follicles but decreases with follicle development. This transcription factor might be a repressor of ovarian differentiation genes in the granulosa cells and play a role in arresting the differentiation of immature follicles.
Mol Endocrinol 1995 Oct
PMID:Wilms' tumor protein WT1 as an ovarian transcription factor: decreases in expression during follicle development and repression of inhibin-alpha gene promoter. 854 44

Restriction fragment length polymorphisms were identified in sheep and deer using ovine cDNA probes for the FSH receptor (FSHR) and the LH receptor (LHCGR). FSHR and LHCGR were closely linked in sheep with no recombinants and neither receptor was linked to the Booroola fecundity gene (FecB). Both receptors were also closely linked in deer at a map distance of 3.3 cM. Linkage between the receptor genes assigns FSHR to sheep chromosome 3. Sequence analysis showed that the mammalian LHCGRs and FSHRs are more similar to each other than to mammalian TSH receptor (TSHR). Taken together, these data suggest that TSHR and the LHCGR/FSHR arose from a common ancestral gene by a process of chromosomal duplication. Subsequent duplication of the region containing the LH/FSH receptor and functional divergence could have given rise to the two gonadotrophin receptors present in mammals today.
J Mol Endocrinol 1995 Dec
PMID:The follicle-stimulating hormone receptor and luteinizing hormone receptor genes are closely linked in sheep and deer. 874 32

A key question in elucidating the role of FSH in ovarian function is to determine when during follicular growth the FSH receptor first appears. The aim of this study was to examine the site and time of FSH receptor gene expression during early follicular growth. This study was carried out on ovaries of adult sheep during the luteal and prostaglandin-induced follicular phase of the oestrous cycle and also on ovaries of fetal sheep at 90, 100, 120 and 135 days of gestation (term = day 147). Using reverse transcription-PCR and a set of PCR primers spanning exons 8/9/10, two partial FSH receptor cDNAs (500 and 310 bp) were isolated from adult sheep ovary. It was shown by sequencing that exon 8 was deleted in the 310 bp cDNA, implying that this was part of an alternatively spliced FSH receptor transcript. Using RNA in situ hybridisation on ovaries of adult sheep, FSH receptor mRNA was observed in granulosa cells of early preantral follicles with one to two cell layers and it was seen that gene expression continued throughout folliculogenesis into advanced stages of atresia. Moreover, in the fetus, FSH receptor gene expression was detected in follicles with two or more layers of granulosa cells in ovaries taken at 100, 120 and 135 days of gestation. These results suggest that the FSH receptor gene is expressed after the granulosa cells of a follicle have begun to divide but not during the earliest stages of follicle growth, namely the transformation of a primordial follicle to a primary follicle.
J Mol Endocrinol 1995 Dec
PMID:FSH receptor gene expression during ovarian follicle development in sheep. 874 34

Prolonged stimulation of gonadotropin receptors in granulosa cells leads to desensitization of the cellular response to gonadotropic hormones which is evident by decrease in cAMP formation. In order to explore the mechanism of desensitization and to examine whether protein phosphorylation may play a role in this phenomenon, we have studied the effect of various stimulators and inhibitors of protein phosphorylation on FSH-induced cAMP formation in the FSH-responsive cell line, GFSHR-17, recently established in our laboratory. Both ovine and human FSH activated the hormone sensitive adenylate cyclase in a dose-dependent manner with an ED50 of 0.5 nM. This stimulation was followed by a sharp decrease in cAMP formation after 30 min incubation of the cell with the hormone. When cells were preincubated for 60 min with staurosporine, cAMP accumulation during 20 min of FSH stimulation was elevated about 500%, compared to cells stimulated by FSH alone. Staurosporine alone showed a negligible effect on cAMP accumulation in these cells. In cells stimulated with forskolin, a non-specific activator of adenylate cyclase, or with cholera toxin (CT), an inhibitor of GTPase activity associated with Gs of adenylate cyclase, preincubation with staurosporine increased cAMP formation in these cells by only 50-70 or 80-120%, respectively. Preincubation of cells with the protein kinase C (PKC) inhibitors chelerythrine and GF109203X increased FSH-stimulated accumulation of cAMP by 50 and 30%, respectively. These drugs exhibit a similar effect on forskolin-stimulated cells. Preincubation of cells for 60 min with a PKC stimulator, TPA, suppressed FSH-mediated cAMP response in these cells by 40%. Tyrosine kinase inhibitors such as AG18, AG33 and genistein exhibit a modest inhibitory effect of up to 20% on FSH-stimulated cAMP accumulation. All the above results were obtained both in the presence and absence of IBMX, a potent inhibitor of the cellular phosphodiesterases. Upon prolonged incubation with FSH (3 h) cells pretreated with staurosporine exhibited a much slower rate of decline in intracellular cAMP levels. Moreover, in desensitized cells, following 1 or 2 h of continuous stimulation with FSH, staurosporine could markedly enhance cAMP formation in the presence of FSH. Our data suggest that staurosporine-sensitive phosphorylation of serine or threonine in the FSH receptor-cyclase system may be responsible for desensitization of the FSH coupled activation of cAMP formation, while reactivation of the system can be achieved by protein dephosphorylation at these specific sites. Because specific inhibition of PKC could not mimic the staurosporine effect on FSH-stimulated cAMP formation, nor could activation of kinase C antagonize it, it is suggested that a specific staurosporine-sensitive receptor kinase may be responsible for modulation of the coupling between the gonadotropin receptor and the adenylate cyclase system.
Mol Cell Endocrinol 1996 Jan 15
PMID:Activation of FSH-responsive adenylate cyclase by staurosporine: role for protein phosphorylation in gonadotropin receptor desensitization. 882 63

Gonadotropin and TSH receptors represent a subgroup of seven transmembrane-spanning, G protein-coupled receptors with a large extracellular ligand-binding region. After ligand binding to their receptors, the majority of actions of gonadotropins and TSH are believed to be mediated by the cAMP-protein kinase A pathway. Although formation of inositol phosphates (IP) has been reported after stimulation of rodent gonadotropin receptors, activation of phospholipase C after ligand binding of human LH or FSH receptors has not been investigated. Human gonadotropin receptors were transiently expressed in 293 cells, and the agonist-induced stimulation of IP formation was measured. The LH receptor responded to a saturating dose of human CG (hCG) with a 5.2-fold increase of IPs whereas the FSH receptor responded to a saturating dose of FSH with only a 50% increase. On the basis of these differences and in view of the homologous nature of the two gonadotropin receptors, chimeric receptors were constructed using domain transfer to identify the regions in the human LH receptor important for phosphatidylinositol hydrolysis. Chimeric receptors containing the entire extracellular region of the FSH receptor and the seven transmembrane region plus the cytoplasmic tail of the LH receptor responded to FSH treatment with a 4.7-fold increase in IP accumulation. In contrast, the chimeric receptor with the extracellular region of the LH receptor and the TM region plus the cytoplasmic tail of the FSH receptor responded minimally (50%) to hCG treatment. When the C-terminal third (from TM V to the cytoplasmic tail) of the FSH receptor was replaced with the LH receptor sequence, the chimeric receptor still responded to FSH treatment with a large (6.2-fold) increase in IP release, similar to that of the wild type LH receptor (to hCG), suggesting that C-terminal third of the human LH receptor confers IP signaling ability. This functional domain was further divided into two areas, namely TM V to TM VI and TM VII to the cytoplasmic tail. The chimeric receptors F(I-IV)L(V-VI)F(VII-C)R and F(I-VI)L-VII-C)R, in which these two regions of the FSH receptor were replaced by the corresponding sequences of the LH receptor, responded to FSH treatment with partial increases in phosphatidylinositol hydrolysis (2.0- and 3.7-fold, respectively). Furthermore, when TM VII and the cytoplasmic tail of the LH receptor were replaced with the corresponding sequence of the FSH receptor, this chimeric receptor showed a diminished (2.0-fold) response to hCG in IP release. For all the chimeric receptor constructs analyzed, overall expression, equilibrium binding constants, and adenyl cyclase activation were not altered. Thus, unlike studies using chimeric muscarinic and dopaminergic receptors in which the second and third intracellular loops were found to be important for IP signaling, the entire C-terminal third of the human LH receptor is important for IP release. Future analysis using the chimeric receptor approach should provide new information on the structure-function relationship of gonadotropin, TSH, and other seven transmembrane-spanning receptors.
Mol Endocrinol 1996 Sep
PMID:The C-terminal third of the human luteinizing hormone (LH) receptor is important for inositol phosphate release: analysis using chimeric human LH/follicle-stimulating hormone receptors. 888 47


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>