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Biological Functions of N- and O-linked Oligosaccharides of Equine Chorionic Gonadotropin and Lutropin/Chorionicgonadotropin Receptor

  • Min, K. S.
    • Proceedings of the KSAR Conference
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    • 2000.10a
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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.

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Conceptions Toward Career Development and Occupational View between Giftedness in Computer Science and Normal Students in Elementary School (초등정보과학영재와 일반학생의 진로발달 및 직업관 인식에 대한 조사 연구)

  • Lee, Jaeho;Choi, Seung Hee
    • Journal of Gifted/Talented Education
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    • v.24 no.4
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    • pp.613-628
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    • 2014
  • The purpose of this study is to compare the differences of the career development and the occupational view between giftedness in computer science and normal students in elementary school, so the results of this study provide assistance to the teacher for the direction and guidance on the career education of the giftedness in computer science in elementary school. This survey is based on 82 giftedness in computer science and 167 normal elementary school students. The questionnaires used in the study contain questions asking regarding the career development and the occupational view. The results of this study were as follows : First, according to the consciousness analysis result about career, the giftedness in computer science choose to be scientific technicians, the normal students choose to be artists. The both groups get career information from their parents, but they usually don't get career counseling from teachers. The education of giftedness in computer science does not contribute to changing their dreams, while normal students have no interest in computer science. Second, according to the career development analysis result, in comparison with non-gifted students, the gifted in information science had more success in all domains of career development. Third, according to the occupational view analysis result, the information science gifted students had higher meaningful rate than the normal students. Intrinsic domain' had higher meaningful rate among the subordinate domains, there is no difference in 'extrinsic domain' and 'incidental domain' between the information science gifted students and the normal students. Fourth, according to the correlation analysis result of the career development and the occupational view, there is a positive correlation in all domains of them. The high they are in the career development, the more they have the certain occupational view. Likewise, if they have the certain occupational view, they will be more successful in career development. Based on the findings of this research, the directing and guidance on the career education of giftedness in computer science in elementary school is same as the followings. We should educate parents regarding information about career for students who are under the influence of parents greatly and indicate them to apply to their children appropriately. In addition, for making them to have the positive image of the computer science, teacher should provide more information about the area of information and form various curriculums to induce more interests about computer science. We need to strengthen the career education for guiding the gifted to assist them to establish their own goal and realize them how to study and choose their career in the future. In school education field, it must develop and manage the definite and empirical program, not the career development program which is focused on only entrance into advanced school, to boost self-realization ability and the suitable career education program based on the correct understanding on giftedness in computer science. For this, through steady trying and research, teachers should be eater to develop the career education for students. Also, we have to implement the internal stability career education program, so it will help students to be aware of their job and career; therefore, students will be able to plan and prepare for their career in this rapid changing world.

Efficacy of mechanical pleurodesis for the treatment of spontaneous pneumothorax with VATS - A comparison of short-term recurrence according to the intensities of pleural abrasion - (비디오 흉강경을 이용한 자연기흉 수술에서 기계적 흉막유착술의 효과 -기계적 흉막유착술의 강도에 따른 단기 재발율의 비교-)

  • 허진필;이정철;정태은;이동협;한승세
    • Journal of Chest Surgery
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    • v.31 no.11
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    • pp.1070-1075
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    • 1998
  • Background: With the advent of thoracoscopy, there has been increasing interest in less invasive surgical bullectomy and pleurodesis. The recurrence rate, however, has been reported higher in surgery with thoracoscopy than with open thoracotomy and it is thought to be caused by inappropriate mechanical pleurodesis during thoracoscopic surgery. Materials and methods: We compared the short-term recurrence rates according to the intensities of pleural abrasion in 62 patients who underwent VATS for treatment of spontaneous pneumothorax from April 1996 to August 1997. The patients were divided into 2 groups: group A(n=32) included patients who received relatively weak pleural abrasion using Endo-forcep instrument for grasping the gauze, and group B(n=30) received strong pleural abrasion using conventional instrument wrapped tightly with gauze. Each intensity of pleural abrasion allowed petechia on the parietal pleura in group A, and some tearing and bleeding in group B. Results: Indications for operation, sex distribution, and age were comparable in both groups. There were no differences in chest tube indwelling time(3.78±3.35 vs 3.80±2.49 days), hospital stay(4.72±1.87 vs 4.67±2.20 days), and the amount and duration of analgesics required postoperatively. Persistent air-leak more than 7 days after surgery occurred in 4/32(12.5%) and 2/30(6.7%) in group A and B, respectively. No bleeding-related complication occured. Pneumothorax recurred 12.5%(4/32) and 0%(0/30) of patients at a mean follow-up of 9.7 and 9.6 months in group A and B, respectively, and it was statistically significant(p<0.05). Conclusions: Proper intensity of pleural abrasion is very important factor to reduce recurrence after VATS for spontaneous pneumothorax. During short-term follow-upafter surgery, we could achieve excellent result in reducing recurrence rate with VATS and strong pleural abrasion which is comparable to thoracotomy.

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ALL-SKY OBSERVATION OF THE 2001 LEONID METEOR STORM: 1. METEOR MAGNITUDE DISTRIBUTION (전천 카메라를 이용한 2001 사자자리 유성우 관측: 1. 유성 등급 분포)

  • 김정한;정종균;김용하;원영인;천무영;임홍서
    • Journal of Astronomy and Space Sciences
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    • v.20 no.4
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    • pp.283-298
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    • 2003
  • The 2001 Leonid meteor storm has been observed all over the world, and its most intense flux since the last few decades has caused great interest among both laymen and experts. Especially, its maximum hours occurred at dawn hours of Nov. 19 in the east Asia, during which moonless clear night at the Mt. Bohyun allowed us near perfect condition of observation. Observation was carried out in the period of 01:00∼05:40(KST), which include the predicted maximum hours, with all-sky camera installed for upper atmospheric airglow research. Tn this paper we analyze 68 all-sky images obtained in this period, which contain records of 172 meteors. Utilizing the zenith hourly rate(ZHR) of 3000 and magnitude distribution index of 2, which were reported to International Meteor Organization by visible observers in the east Asia, we estimate the limiting magnitude of about 3 for meteors detected in our all-sky images. We then derive magnitudes of 83 meteors with clear pixel brightness outlines among the initially detected 172 meteors by comparing with neighbor standard stars. Angular velocities of meteors needed for computing their passing times over an all-sky image are expressed with a simple formula of an angle between a meteor head and the Leonid radiant point. The derived magnitudes of 83 meteors are in the range of -6∼-1 magnitude, and its distribution shows a maximum new -3mag. The derived magnitudes are much smaller than the limiting magnitude inferred from the comparison with the result of naked-eye observations. The difference may be due to the characteristic difference between nearly instantaneuous naked-eye observations and CCD observations with a long exposure. We redetermine magnitudes of the meteors by adjusting a meteor lasting time to be consistent with the naked-eye observations. The relative distribution of the redetermined magnitudes, which has a maximum at 0 mag., resembles that of the magnitudes determined with the in-principle method. The relative distribution is quite different from ones that decrease monotonically with decreasing magnitudes for meteors(1∼6) sensitive to naked-eye observations. We conclude from the magnitude distribution of our all-sky observation that meteors brighter than about 0 mag., appeared more frequently during the 2001 Leonid maximum hours. The frequent appearance of bright meteors has significantly important implication for meteor research. We noted, however, considerably large uncertainties in magnitudes determined only by comparing standard stars due to the unknown lasting time of meteors and the non-linear sensitivity of all-sky camera.

Spatial Structure of Hinterlands and Forelands of Pusan Container Export Port: the Cases of 3 National Flag Carriers (부산 컨테이너 수출항의 배후지와 지향지의 공간구조)

  • Cho, Su-Kyung
    • Journal of the Korean Geographical Society
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    • v.28 no.3
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    • pp.247-267
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    • 1993
  • According to developing international economy since the World War II, the increase and competition of the national business is so empha-sized tht both the interest and the necessity about marine transportation playing the impor-thant role of international transportation are increased. Today, the container transportation, as called the innovation of marine transport has been prevailed since the 1970's. The purpose of this paper is to grasp the spatial structure of the hinterlands and forelands, its object is export container cargo at Pusan Export Port, as known for the transportation node of modern containerlization. In this study, for the purpose of grasping the relation between hinterlands and forelands of Korean export container cargo, first, I researched the transition of carloading about container cargo, the bistribution channel of cargo, the change of the items of container and the carlo-adings about transport route, secondly, I used the cluster analysis so as to group hinterlands according to the items of goods and forelands. The object of the analysis is container cargo of Choyang Line, Hanjin Shipping and Hyundai Merchant Marine of National Frag Carriers. The source materials used in this study are Trucking Data of Hanjin Co., Container Ren-tal Data of Samik Transport Co. and Transpor-ting Present Condition Tables of Hyundai Mer-chant Marine. 1. There are two kinds of the transport classi-fied by its form: FCL and LCL. In Pusan Con-tainer Export, a lot of textile goods, clothings and furniture, compound, electric goods, and so on are dealed with but the rate of occupation of the transport is getting lower while that of occupation of equipment, papers and agricultu-ral, mineral and livestock industry higher. 2. In 1990, the transports of container cargo in Korea consist of 7 services and round-the world lines. We can list North America lines, East-South Asian lines, Japan lines and Inter European lines, in order of the quantity of tran-sport form the largest to the smaller. We can have another list that Japan lines, North Ame-rica lines and East-South lines in order of the rate participation of national flag carriers, be-cacuse Korean foreign trade lay disproportionate emphasis on East-South Asian lines. Japan lines among them is the biggest import-export market. Since the rationlization policy of marine tran-sport in 1984, each of national flag carriers have its own lines. Hanjin Shipping predominates over North America lines, Choyang Line over New Zealand, Inter European and Austria lines and Hyundai Merchant Marine over Center-South America lines, in terms of the volume of transport. And small-to-medium sized shippers are prevailing in lines which are adjacent to Korea, Such as Japan lines and East-South Asian lines. 3. In relation to hinterlands and forelands of Choyang Line, the light industry goods, electric goods and machinary produced in Seoul and Pusan are exported to the major ports in Europe and Japan, the same produces in Suwon, Ulsan, Kumi are exported to European Ports, and those in Incheon and Kwangju Austrian and Japanese ports, and those in the rest regions to the major port in Japan. 4. In relation to hinterlands and forelands of Hanjin Shipping, the light industry goods pro-ducing in Seoul and Pusan, the electric goods and machinary in Incheon and Pyeongteck, are exported to New York and Los Angeles. Electric goods and machinary Masan, Anyang, Cheona, Cheongju and Incheon, Electric goods machinary and light industry goods in Kwangju and non mental goods in Pohang, are exported New York, Los Angeles and Oakland. 5. In relation to hinterlands and forelands of Hyundai Merchant Marine, the region of Seoul, Pusan and Incheon closely related with the main ports in U.S.A. The rest regions with Montreal. The hinterlands of export container cargo can be classified by its export items into three kinds: the large city, industrial city and the rest city. Choyang Line's forelands are European lines, Japan lines and Austria lines, and Hanjin Shipping's forelands are North America lines, and Hyundai Merchant Marine's forelands are North America lines and Japan line. 3 National flag carriers' major forelands are determined by the size of port and the shipper's convenient use of the port terminal.

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Variation Analysis of Distance and Exposure Dose in Radiation Control Area and Monitoring Area according to the Thickness of Radiation Protection Tool Using the Calculation Model: Non-Destructive Test Field (계산 모델을 활용한 방사선방어용 도구 두께에 따른 방사선관리구역 및 감시구역의 거리 및 피폭선량 변화 분석 : 방사선투과검사 분야 중심으로)

  • Gwon, Da Yeong;Park, Chan-hee;Kim, Hye Jin;Kim, Yongmin
    • Journal of the Korean Society of Radiology
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    • v.14 no.3
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    • pp.279-287
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    • 2020
  • Recently, interest in radiation protection is increasing because of the occurrence of accidents related to exposure dose. So, the nuclear safety act provides to install the shields to avoid exceeding the dose limit. In particular, when the worker conducts the non-destructive testing (NDT) without the fixed shielding structure, we should monitor the access to the workplace based on a constant dose rate. However, when we apply for permits for NDT work in these work environments, the consideration factors to the estimation of the distance and exposure dose are not legally specified. Therefore, we developed the excel model that automatically calculates the distance, exposure dose, and cost if we input the factors. We applied the assumption data to this model. As a result of the application, the distance change rate was low when the thickness of the lead blanket and collimator is above 25 mm, 21.5 mm, respectively. However, we didn't consider the scattering and build-up factor. And, we assumed the shape of the lead blanket and collimator. Therefore, if we make up for these limitations and use the actual data, we expect that we can build a database on the distance and exposure dose.

Eating Habits of Children Under 4 Years with Poor-Feeding (식욕부진이 있는 4세 이하 영.유아의 식이 습관에 대한 조사)

  • Yoon, Young-Hun;Park, Yeung-Bong;Yang, Eun-Seok;Rho, Young-Ill;Kim, Eun-Young;Moon, Kyung-Rye;Lee, Chul-Gab
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.6 no.2
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    • pp.167-173
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    • 2003
  • Purpose: To find out the differences in eating habits between poor feeding and non-poor feeding children. Methods: We performed questionnaires on 504 children under four years of age who visited hospitals in Gwangju city and JaollaNamdo from May to August, 2002. Results: 138 (27.4%) children were included in poor feeding group, and 366 (72.%) children were in non-poor feeding group. Breast feeding rate was 18.8% in the poor feeding group and 20.3% in the non-poor feeding group. Duration of breast feeding for less than six months were noted in 70.5% of poor feeding group, and 58.5% of non-poor feeding group. The time at starting solid food in the poor feeding group was as follows; 15.9% of infants started on solid food when they were 2~4 months old, 32.7% during 4~6 months, 38.1% during 6~8 months and 18.8% over one year of age. Solid food was given in wrongly manners in both groups by nursing bottles, including 80.4% in poor feeding group and 66.6% in non-poor feeding group. Conclusion: This study demonstrated close relationships among poor feeding children under four years of age with history of low rate and short duration of breast feeding, inappropriate time to start on solid food, less interest in food during mealtime, and unbalanced diet. Pediatricians should make an effort to play an important role in nutritional education and treatment in children.

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Estimation of Groundwater Recharge by Considering Runoff Process and Groundwater Level Variation in Watershed (유역 유출과정과 지하수위 변동을 고려한 분포형 지하수 함양량 산정방안)

  • Chung, Il-Moon;Kim, Nam-Won;Lee, Jeong-Woo
    • Journal of Soil and Groundwater Environment
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    • v.12 no.5
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    • pp.19-32
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    • 2007
  • In Korea, there have been various methods of estimating groundwater recharge which generally can be subdivided into three types: baseflow separation method by means of groundwater recession curve, water budget analysis based on lumped conceptual model in watershed, and water table fluctuation method (WTF) by using the data from groundwater monitoring wells. However, groundwater recharge rate shows the spatial-temporal variability due to climatic condition, land use and hydrogeological heterogeneity, so these methods have various limits to deal with these characteristics. To overcome these limitations, we present a new method of estimating recharge based on water balance components from the SWAT-MODFLOW which is an integrated surface-ground water model. Groundwater levels in the interest area close to the stream have dynamics similar to stream flow, whereas levels further upslope respond to precipitation with a delay. As these behaviours are related to the physical process of recharge, it is needed to account for the time delay in aquifer recharge once the water exits the soil profile to represent these features. In SWAT, a single linear reservoir storage module with an exponential decay weighting function is used to compute the recharge from soil to aquifer on a given day. However, this module has some limitations expressing recharge variation when the delay time is too long and transient recharge trend does not match to the groundwater table time series, the multi-reservoir storage routing module which represents more realistic time delay through vadose zone is newly suggested in this study. In this module, the parameter related to the delay time should be optimized by checking the correlation between simulated recharge and observed groundwater levels. The final step of this procedure is to compare simulated groundwater table with observed one as well as to compare simulated watershed runoff with observed one. This method is applied to Mihocheon watershed in Korea for the purpose of testing the procedure of proper estimation of spatio-temporal groundwater recharge distribution. As the newly suggested method of estimating recharge has the advantages of effectiveness of watershed model as well as the accuracy of WTF method, the estimated daily recharge rate would be an advanced quantity reflecting the heterogeneity of hydrogeology, climatic condition, land use as well as physical behaviour of water in soil layers and aquifers.

Analysis of Coexistence Rates of Attention Deficit/Hyperactivity Disorder Symptoms in Patients with Depression (우울감을 주소로 내원한 환자들에서 주의력 결핍/과잉행동장애 증상의 공존율 분석)

  • Jeong, Mi Young;Park, Seo Young;Kim, Jung Ho;Im, Woo Young;Lee, Yeon Jung
    • Korean Journal of Psychosomatic Medicine
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    • v.27 no.2
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    • pp.147-154
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    • 2019
  • Objectives : Cognitive dysfunction, including inattention, is often observed in patients with depression. Inattentive symptoms in patients with depression is similar to those among attention deficit/hyperactivity disorder (ADHD) patients. It is important to diagnose the two diseases accurately, because the treatment varies depending on the cause of inattention. This study aimed to investigate the coexistence rate of ADHD and the correlation between ADHD symptoms and depression in patients with depression. Methods : Participants in this study were 158 outpatients presenting with depression, who visited the psychiatric department from March 2015 to July 2018. Participants divided into a depression and a non-depression group according to the Korean version of the Center for Epidemiological Studies-Depression Scale (CES-D) score and were administered the following : a sociodemographic variables form (age, sex, academic background, occupation), the self-reporting test for adult ADHD (Adult Attention Deficit/Hyperactivity Disorder self-report scale-V 1.1; ASRS V1.1), and the Korean version of the Connors adult ADHD rating scale (K-CAARS). Descriptive statistical analysis, crossover analysis, t-tests, and Pearson's correlation coefficient were conducted on the data. Results : The coexistence rate of adult ADHD symptom was as high as 36.7% in patients with depression (p<0.001). In K-CAARS, the depression group (Inattention=1.80, Hyperactivity=1.92, Impulsivity=1.56, Self-concept=2.06) showed higher average scores on ADHD symptoms than the non-depressive group (Inattention=1.28, Hyperactivity=1.25, Impulsivity=1.09, Self-concept=1.42, p<0.001). Conclusions : This study confirmed that ADHD symptoms coexist in the depression group. When evaluating the symptoms of patients who complain of depression, it is suggested that they should be accurately diagnosed and appropriately treated with interest to the coexistence of ADHD symptoms and the possibility for ADHD diagnosis.

Biological Functions of N- and O-linked Oligosaccharides of Equine Chorionic Gonadotropin and Lutropin/Chorionic Gonadotropin Receptor

  • Min, K.S.
    • Korean Journal of Animal Reproduction
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    • v.24 no.4
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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.

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