• Korean Journal of Animal Reproduction
• /
• v.24 no.4
• /
• pp.357-364
• /
• 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.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.15 no.1
• /
• pp.29-34
• /
• 2015

Citrullinemia type1 is an autosomal recessive disorder of the urea cycle characterized by neonatal or late onset of hyperammonemia caused by a deficiency of the enzyme argininosuccinate synthetase (ASS). An ASS1 deficiency demonstrates fatal clinical manifestations that are characterized by the neonatal metabolic coma and early death when untreated. It causes a broad spectrum of effects, ranging from a mild disorder to a severe mental retardation, epilepsy, neurologic deficits. An acute neonatal form is the most common. Infants are normal at birth followed by an acute illness characterized by vomiting, lethargy, seizures and coma. These medical problems are life-threatening in many cases. A later onset form is less frequent and may be milder than the neonatal form. This later-onset form is associated with severe headaches, visual dysfunction, motor dysfunction, and lack of energy. Citrullinemia type1 is caused by mutations in the ASS1 gene located on chromosome 9q34.1 that encodes argininosuccinate synthetase, the third enzyme of the urea cycle catalyzing the formation of argininosuccinic acid from citrulline and aspartic acid. The enzyme is distributed in tissues including liver and fibroblasts. This mutation leads to hyperammonemia, arginine deficiency and elevated citrulline level. In the urea cycle, argininosuccinate synthetase catalyses the conversion of citrulline and aspartate to argininosuccinate.. Here, we describe a female newborn patient with lethargy, rigidity and hyperammonemia who was diagnosed as citrullinemia type1 with a c.[421-2A>G], c.[1128-6_1188dup] mutation.

• Journal of Life Science
• /
• v.15 no.3 s.70
• /
• pp.479-485
• /
• 2005

The 994 throat swabs obtained from 688 adults and 306 children patients with respiratory diseases were examined for Mycoplasma pneumoniae infection by culture method. Antimicrobial susceptibilities of the resulting 123 M. pneumoniae isolates were evaluated by testing minimum inhibitory concentrations (MICs) of erythromycin, minocycline, tetracycline, josamycin, sparfloxacin, ofloxacin, and ciprofloxacin by a broth micro-dilution method. The erythromycin resistant strains of M. pneumoniae was determined above $1.0{\mu}g/ml$ of MIC for erythromycin. The erythromycin resistant strains of M. pneumoniae was confirmed resistant gene mutation of the portions of genes 23S rRNA (domain II and V), and ribosomal protein 14 and L22 by PCR amplified and their nucleotide sequenses were compared to those of the susceptible strain M129. The isolation rate of M. pneumoniae was $12.9\%$ (89/688) for the adults and $11.1\%$ (34/306) for the children. The $MICs_{90}$ of the M. pneumoniae isolates were $0.12{\mu}g/ml$ for minocycline, $0.25{\mu}g/ml$ for sparfloxacin, $0.5{\mu}g/ml$ for ciprofloxacin, ofloxacin, and tetracycline, respectively, and $2.0{\mu}g/ml$ for josamycin and erythromycin, respectively. The isolation rate of erythromycin resistant M. pneumoniae from patients was $49.4\%\;(44/89)$ for the adults, $47.1\%\;(16/34)$ for children, and $48.8\%\;(60/123)$ for the total. No mutation could be detected in the ribosomal protein L22 region, but all strains were mutated in the ribosomal protein L4 as two point mutation M144V. Two point mutations in domain V of 23S rRNA were selected in the presense of erythromycin resistant M. pneumoniae isolates, such as one strain was G2057C mutant, two strains were A2059C mutants, three strains were C2611G mutants, four strains were A2058C mutants, five strains were A2058T mutants, twenty strains were A2059G mutants, and twenty-five strains were A2058G mutants, respectively. These results show that erythromycin was not the most active compound against M. pneumoniae infection in Korea and clinical studies of macrolides in human patients are demanded.

• Journal of Life Science
• /
• v.24 no.8
• /
• pp.820-826
• /
• 2014

The localization to specific subcellular sites and the regulation of cell surface receptors and channels are crucial for proper functioning. Postsynaptic density-95/Disks large/Zonula occludens-1 (PDZ)-domain is involved in recognition of and interaction between various proteins, by which the localization and the regulation are mediated. Multi-PDZ domain protein 1 (MUPP1) contains 13 PDZ domains. MUPP1 serves a scaffolding function for structure proteins and signaling proteins, but the mechanism how MUPP1 is stabilized and signalized has not yet been elucidated. We used the yeast two-hybrid system to identify proteins that interact with PDZ domains of MUPP1. We found an interaction between MUPP1 and Parkin. Parkin is an E3 ubiquitin ligase. Loss-of-function mutations of Parkin gene are known to cause an autosomal recessive juvenile parkinsonism. Parkin bound to the $12^{th}$ PDZ domain, but not to other PDZ domains of MUPP1. The C-terminal end of Parkin has a type II PDZ-association motif, which was essential for the interaction with MUPP1 in the yeast two-hybrid assay. When co-expressed in HEK-293T cells, Parkin co-localized with MUPP1. When co-expressed with ubiquitin in HEK-293T cells, MUPP1 has been strongly ubiquitinated by Parkin. These findings collectively suggest that MUPP1 is a novel substrate of Parkin and its function or stability could be modulated by Parkin-mediated ubiquitination.

• Journal of Life Science
• /
• v.31 no.10
• /
• pp.913-921
• /
• 2021

Limb-girdle muscular dystrophy (LGMD) which is characterized by progressive muscle weakening of the hip and shoulder shows both dominant and recessive inheritances with many pathogenic genes including TTN. This study performed to identify genetic causes of a male patient with late onset (45 years old) autosomal recessive LGMD and atrial flutter. By application of the whole exome sequencing, we identified bi-allelic variants of TTN gene in the patient. One allele had a single missense variant of [c.24124G>T (p.V8042F)], while the other allele consisted of three missense variants of [c.29222G>C (p.R9741P) + c.67490A>G (p.H22497R) + c.75376C>T (p.R25126C)]. The p.V8042F allele was transmitted from his mother, while the other haplotype allele was putatively transmitted from his father. His two unaffected sons had only the p.R9741P. These variants have been not reported or rarely reported in the public human genome databases (1,000 Genome, gnomAD, and KRGDB). Most variants were located in the highly conserved immunoglobulin or fibronectin domains and were predicted to be pathogenic by the in silico analyses. The TTN giant protein plays a key role in muscle assembly, force transmission at the Z-line, and maintenance of resting tension in the I-band. In conclusion, we think that these bi-allelic compound heterozygous mutations may play a role as the genetic causes of the LGMD phenotype.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.21 no.1
• /
• pp.7-14
• /
• 2021

Purpose: Pseudohypoparathyroidism (PHP) is caused by genetic and epigenetic alteration in the GNAS locus, and characterized by the resistance to multiple hormones and the Albright's hereditary osteodystrophy (AHO) phenotype. This study investigated the phenotypic characteristics and molecular features of PHP. Methods: Eight patients who diagnosed as PHP were enrolled at Pusan National University Children's hospital and clinical features, biochemical and genetic findings were retrospectively reviewed. Results: Of a total of 8 patients, 5 were diagnosed with PHP1a, and 3 were diagnosed with PHP1b. Patients with PHP1a had three different mutations in the GNAS gene, and patients with PHPIb had imprinting defect in differentially methylated regions (DMRs) of the GNAS locus. Two novel GNAS variants were identified in patients with PHP1a, including c.313-2A>T and c.1094G>A. All patients with PHP1a displayed AHO features; short stature (80%), brachydactyly (80%), a round face (80%), obesity (40%), heterotopic ossification (60%), and intellectual disability (60%), whereas only one patient (33.3%) with PHP1b showed AHO feature such as a round face. When phenotypic features between PHP1a and PHP1b patients were compared, patients with PHP1b showed a tendency of higher current height standard deviation scores (SDS) compared to patients with PHP1a, (-3.2±2.1 vs.-1.1±0.8; P=0.06) Conclusions: This study summarizes the phenotypic and genetic features of the PHP patients. Although we found considerable clinical overlap between PHP1a and PHP1b, further long-term follow-up is needed to evaluate the growth and development of children with PHP, as well as the effects of end-organ resistances to endocrine hormones.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.22 no.2
• /
• pp.58-62
• /
• 2022

Pompe disease (PD) is an autosomal recessive genetic disorder caused by a deficiency of the lysosomal enzyme acid α-glucosidase (GAA). It is easy to hastily diagnose as patients if they have two pathogenic variants. Clinical pathologists misdiagnosed our infant and her mother as PD. Here, we report a case of pseudodeficiency in a potential late-onset Pompe disease (LOPD) carrier with a double dual variant, each in cis formation in a 3-month infant. The person who has two pathogenic variants was diagnosed as a carrier, not a patient. It was first reported in Korea. The patient had: two likely pathogenic heterozygous mutations on exon #4: c.752C>T (p.Ser251Leu), c.761C>T (p.Ser254Leu), and a heterozygous mutation on exon #12: c.1726G>A (p.Gly576Ser), also with a heterozygous mutation on exon #15: c.2065G>A (p.Glu689Lys). By presenting this case we emphasize the possibility of cis formation of genes which may cause pseudodeficiency, and potential LOPD carrier form. Hereby we suggest that thorough evaluation of GAA gene is essential among whom initially diagnosed as PD.

• Journal of Life Science
• /
• v.33 no.10
• /
• pp.808-819
• /
• 2023

This study was conducted to develop a selection marker for the identification of the Bacillus licheniformis K12 strain in microbial communities. The strain not only demonstrates good growth at moderate temperatures but also contains enzymes that catalyze the decomposition of various polymer materials, such as proteases, amylases, cellulases, lipases, and xylanases. To identify molecular markers appropriate for use in a microbial community, a search was conducted to identify variable gene regions that show considerable genetic mutations, such as recombinase, integration, and transposase sites, as well as phase-related genes. As a result, five areas were identified that have potential as selection markers. The candidate markers were two recombinase sites (BLK1 and BLK2), two integration sites (BLK3 and BLK4), and one phase-related site (BLK5). A PCR analysis performed with different Bacillus species (e.g., B. licheniformis, Bacillus velezensis, Bacillus subtilis, and Bacillus cereus) confirmed that PCR products appeared at specific locations in B. licheniformis: BLK1 in recombinase, BLK2 in recombinase family protein, and BLK3 and BLK4 as site-specific integrations. In addition, BLK1 and BLK3 were identified as good candidate markers via a PCR analysis performed on subspecies of standard B. licheniformis strains. Therefore, the findings suggest that BLK1 can be used as a selection marker for B. licheniformis species and subspecies in the microbiome.

• Journal of Life Science
• /
• v.34 no.2
• /
• pp.86-93
• /
• 2024

Since replication of plasmids must be strictly controlled, plasmids that generally perform rolling circle replication generally maintain a constant copy number by strictly controlling the replication initiator Rep at the transcriptional and translational levels. Plasmid pJB01 contains three orfs (copA, repB, repC or repABC) consisting of a single operon. From analysis of amino acid sequence, pJB01 CopA was homologous to the Cops, as a copy number control protein, of other plasmids. When compared with a CopG of pMV158, CopA seems to form the RHH (ribbon-helix-helix) known as a motif of generalized repressor of plasmids. The result of gel mobility shift assay (EMSA) revealed that the purified fusion CopA protein binds to the operator region of the repABC operon. To examine the functional role of CopA on transcriptional level, 3 point mutants were constructed in coding frame of copA such as CopA R16M, K26R and E50V. The repABC mRNA levels of CopA R16M, K26R and E50V mutants increased 1.84, 1.78 and 2.86 folds more than that of CopA wt, respectively. Furthermore, copy numbers owing to mutations in three copA genes also increased 1.86, 1.68 and 2.89 folds more than that of copA wt, respectively. These results suggest that CopA is the transcriptional repressor, and lowers the copy number of pJB01 by reducing repABC mRNA and then RepB, as a replication initiator.