• Clinical and Experimental Reproductive Medicine
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• 제25권3호
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• pp.281-286
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• 1998

Premature ovarian failure is a condition causing amenorrhea, hypoestrogenism, and elevated gonadotropins in women younger than 40 years. Many causes of premature ovarian failure were reported, including genetic abnormalities, enzymatic defects, defects in gonadotropin secretion or action, autoimmune disorders, physical and idiopathic causes. Recently, Finnish group reported a point mutation in the follicle stimulating hormone (FSH) receptor gene in premature ovarian failure patients. But it was reported that the group from United States could not find any mutation in FSH receptor gene. So we analysed C566T point mutation of FSH receptor gene using restriction fragment length polymorphism (RFLP) and compared the result between premature ovarian failure patient with idiopathic and known causes. But we did not find 556C${\rightarrow}$T mutation in the FSH receptor gene in both groups. These findings suggest that the missense mutation in the human FSH receptor gene reported in Finnish women with premature ovarian failure is uncommon in Korean women with premature ovarian failure.

• 한국발생생물학회지:발생과생식
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• 제4권1호
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• pp.61-66
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• 2000

본 연구에서는 조기 난소 부전증 환자를 대상으로 난포 자극 호르몬 수용체 유전자의 돌연변이와 발현 양상을 분석하였다. 돌연변이 분석을 위해 환자의 말초혈액에서 genomic DNA를 분리하고 nucleotide 566을 포함하고 있는 exon 7에 특이적인 primer쌍을 이용하여 중합효소 연쇄 반응을 시행하였다. 전기 영동으로 반응산물을 확인한 다음, 돌연변이 여부를 조사하기 위하여 제한효소 절단분석 (Restriction Fragment Length Polymorphism, RFLP)을 시행한 결과, 대조군과 조기 난소 부전증 환자군 모두에서 돌연변이를 관찰할 수 없었다. 난포 자극 호르몬 수용체의 발현양상을 확인하기 위해 시험관아기 시술과정 중 난자 채취과정에서 얻어진 황체화 과립세포에서 total RNA를 추출하여 역전사 중합효소 연쇄 반응을 시행하였다. 반응 산물을 전기 영동하여 발현양상을 비교해 본 결과, 대조군에 비해 조기 난소 부전증 환자군에서 난포 자극 호르몬 수용체 유전자의 발현이 다소 낮은 것으로 확인되었다. 이상의 결과로 보아 조기 난소 부전증 환자에서 난포 자극 호르몬 수용체 유전자의 돌연변이는 발견할 수 없었으며 난포 자극 호르몬 수용체 유전자의 발현이 대조군에 비해 낮아 과배란 유도시에 생식소 자극 호르몬에 대해 저적응증을 보이며 난포형성과정에도 장애를 받는 것으로 사료된다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2000년도 국제심포지움
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• pp.10-12
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$-subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was. efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to consist of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t63I or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632-653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agonist-occupied receptors ~2- and ~17-fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.

• 한국가축번식학회지
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• 제24권4호
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• pp.357-364
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• 2000

Members of the glycoprotein family, which includes CG, LH, FSH and TSH, comprise two noncovalently linked $\alpha$- and $\beta$-subunits. Equine chorionic gonadotropin (eCG), known as PMSG, has a number of interesting and unique characteristics since it appears to be a single molecule that possesses both LH- and FSH-like activities in other species than the horse. This dual activity of eCG in heterologous species is of fundamental interest to the study of the structure-function relationships of gonadotropins and their receptors. CG and LH $\beta$ genes are different in primates. In horse, however, a single gene encodes both eCG and eLH $\beta$ -subunits. The subunit mRNA levels seem to be independently regulated and their imbalance may account for differences in the quantities of $\alpha$ - and $\beta$-subunits in the placenta and pituitary. The dual activities of eCG could be separated by removal of the N-linked oligosaccharide on the $\alpha$-subunit Asn 56 or CTP-associated O-linked oligosaccharides. The tethered-eCG was efficiently secreted and showed similar LH-like activity to the dimeric eCG. Interestingly, the FSH-like activity of the tethered-eCG was increased markedly in comparison with the native and wild type eCG. These results also suggest that this molecular can implay particular models of FSH-like activity not LH-like activity in the eCG/indicate that the constructs of tethered molecule will be useful in the study of mutants that affect subunit association and/or secretion. A single-chain analog can also be constructed to include additional hormone-specific bioactive generating potentially efficacious compounds that have only FSH-like activity. The LH/CG receptor (LH/CGR), a membrane glycoprotein that is present on testicular Leydig cells and ovarian theca, granulosa, luteal, and interstitial cells, plays a pivotal role in the regulation of gonadal development and function in males as well as in nonpregnant and pregnant females. The LH/CGR is a member of the family of G protein-coupled receptors and its structure is predicted to of a large extracellular domain connected to a bundle of seven membrane-spanning a-helices. The LH/CGR phosphorylation can be induced with a phorbol ester, but not with a calcium ionophore. The truncated form of LHR also was down-regulated normally in response to hCG stimulation. In contrast, the cell lines expressing LHR-t631 or LHR-628, the two phosphorylation-negative receptor mutant, showed a delay in the early phase of hCG-induced desensitization, a complete loss of PMA-induced desensitization, and an increase in the rate of hCG-induced receptor down-regulation. These results clearly show that residues 632~653 in the C-terminal tail of the LHR are involved in PMA-induced desensitization, hCG-induced desensitization, and hCG-induced down-regulation. Recently, constitutively activating mutations of the receptor have been identified that are associated with familial male-precocious puberty. Cells expressing LHR-D556Y bind hCG with normal affinity, exhibit a 25-fold increase in basal cAMP and respond to hCG with a normal increase in cAMP accumulation. This mutation enhances the internalization of the free and agoinst-occupied receptors ~2- and ~17- fold, respectively. We conclude that the state of activation of the LHR can modulate its basal and/or agonist-stimulated internalization. Since the internalization of hCG is involved in the termination of hCG actions, we suggest that the lack of responsiveness detected in cells expressing LHR-L435R is due to the fast rate of internalization of the bound hCG. This statement is supported by the finding that hCG responsiveness is restored when the cells are lysed and signal transduction is measured in a subcellular fraction (membranes) that cannot internalize the bound hormone.