Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
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Systemic lupus erythematosus (SLE) is a systemic autoimmune disorder that predominantly affects women of childbearing age, with a female-to-male ratio of approximately 9:1. Previous findings indicated that male cases of SLE were associated with Klinefelter's syndrome (47, XXY), whereas females with Turner's syndrome (45, X0) did not contract SLE. Additionally, duplicated Toll-like receptor 7 (TLR7) was found to promote lupus-like disease. Consequently, the aim of this study was to evaluate whether the TLR7 gene served as a genetic marker for the development of SLE. A case-control study was performed on one tag single nucleotide polymorphism TLR7 rs1634323 in a population with 507 SLE patients and 513 healthy controls. Genotyping was determined by the TaqMan genotyping assay using the ABI 7300 real-time reverse transcription polymerase chain reaction system. The results showed a significantly elevated risk of SLE with the rs1634323 AG genotype in females (P = 0.040, OR = 1.897, 95% CI 1.031-3.491), whereas a similar association was not replicated in males (P = 0.303, OR = 0.338, 95% CI 0.043-2.656). In a subgroup analysis by clinical manifestation of lupus nephritis, no significant differences were found. These findings indicate that the TLR7 gene rs1634323 polymorphism may contribute to SLE susceptibility in females.
Mol Med Rep 2012 Jul
PMID:The TLR7 7926A>G polymorphism is associated with susceptibility to systemic lupus erythematosus. 2250 23

Abnormalities involving sex chromosomes account for approximately 0.5% of live births. The phenotypes of individuals with mosaic cell lines that exhibit structural aberrations of the X and Y chromosomes are variable and difficult to predict. Phenotypes associated with sex chromosome mosaicism vary from females with Turner syndrome to males with infertility, and include individuals with ambiguous genitalia. In this study, we report a 17-year-old male with phenotypic features of Klinefelter syndrome with an isodicentric Y chromosome and a final karyotype of 45,X[4]/46,X,idic(Y)(q11.21)[95]/47,XX,+idic(Y)(q11.21)[1]. Application of high resolution molecular cytogenetic techniques as well as molecular studies revealed two copies of the sex-determining region of Y chromosome (SRY) gene and two centromers. Additionally, the breakpoint in Yq11.21 was narrowed down between positions 13.4 and 14.3 MB (hg18). We present a patient with partial disomy of Ypter to Yq11.21 in the majority of the patient cells, showing phenotypic features of Klinefelter syndrome. The syndrome may have occurred due to a more prominent presence of the cell line 47,XX,+idic(Y)(q11.21) detected only once in 1% of the peripheral blood cells. This finding may prove helpful in similar cases with symptoms of Klinefelter syndrome, but which exhibit an absence of the cell line 47,XXY in peripheral blood.
Mol Med Rep 2012 Aug
PMID:Detailed analysis of an idic(Y)(q11.21) in a mosaic karyotype. 2266 81

Prokineticin receptors (PROKR) are G protein-coupled receptors (GPCR) that regulate diverse biological processes, including olfactory bulb neurogenesis and GnRH neuronal migration. Mutations in PROKR2 have been described in patients with varying degrees of GnRH deficiency and are located in diverse functional domains of the receptor. Our goal was to determine whether variants in the first intracellular loop (ICL1) of PROKR2 (R80C, R85C, and R85H) identified in patients with hypogonadotropic hypogonadism interfere with receptor function and to elucidate the mechanisms of these effects. Because of structural homology among GPCR, clarification of the role of ICL1 in PROKR2 activity may contribute to a better understanding of this domain across other GPCR. The effects of the ICL1 PROKR2 mutations on activation of signal transduction pathways, ligand binding, and receptor expression were evaluated. Our results indicated that the R85C and R85H PROKR2 mutations interfere only modestly with receptor function, whereas the R80C PROKR2 mutation leads to a marked reduction in receptor activity. Cotransfection of wild-type (WT) and R80C PROKR2 showed that the R80C mutant could exert a dominant negative effect on WT PROKR2 in vitro by interfering with WT receptor expression. In summary, we have shown the importance of Arg80 in ICL1 for PROKR2 expression and demonstrate that R80C PROKR2 exerts a dominant negative effect on WT PROKR2.
Mol Endocrinol 2012 Aug
PMID:Evidence of the importance of the first intracellular loop of prokineticin receptor 2 in receptor function. 2274 95

Patients with Kallmann syndrome (KS; congenital hypogonadotropic hypogonadism and decreased/absent sense of smell), septo-optic dysplasia (SOD), or holoprosencephaly (HPE) reportedly have midline defects. In this study, we investigate a genetic overlap between KS, SOD, and HPE. Nineteen subjects (18 males, 1 female) with KS and without mutations in the known KS genes were screened for mutations in SOX2, SHH, SIX3,TGIF1,TDGF1,FOXH1,GLI2, and GLI3. One male carried 2 heterozygous missense changes, one in SIX3 (c.428G>A, p.G143D) and the other in GLI2 (c.2509G>A, p.E837K). Both of these genes have been implicated in the etiology of HPE and neither of these changes were present in 200 control subjects. Other variants found among the subjects were known polymorphisms. KS and HPE may display a genetic overlap. The involvement of genes implicated in the etiology of midline defects in patients with KS warrants further studies.
Mol Syndromol 2012 Jun
PMID:Genetic Overlap between Holoprosencephaly and Kallmann Syndrome. 2285 48

Gonadotropin-releasing hormone (GnRH) plays a major role in the hypothalamic-pituitary-gonadal (HPG) axis, and synthesis and secretion of GnRH are regulated by gonadal steroid hormones. Disruptions in androgen levels are involved in a number of reproductive defects, including hypogonadotropic hypogonadism and polycystic ovarian syndrome. Androgens down-regulate GnRH mRNA synthesis in vivo and in vitro via an androgen receptor (AR)-dependent mechanism. Methyltrienolone (R1881), a synthetic AR agonist, represses GnRH expression through multiple sites in the proximal promoter. In this study, we show AR also represses GnRH transcription via the major enhancer (GnRH-E1). A multimer of the -1800/-1766 region was repressed by R1881 treatment. Mutation of two bases, -1792 and -1791, resulted in decreased basal activity and a loss of AR-mediated repression. AR bound to the -1796/-1791 sequence in electrophoretic mobility shift assays, indicating a direct interaction with DNA or other transcription factors in this region. We conclude that AR repression of GnRH-E1 acts via multiple AR-responsive regions, including the site at -1792/-1791.
Mol Cell Endocrinol 2012 Nov 05
PMID:Androgen receptor repression of gonadotropin-releasing hormone gene transcription via enhancer 1. 2287 52

GnRH, produced in the hypothalamus, acts on pituitary gonadotropes to stimulate release of the gonadotropins LH and FSH. Reduced responsiveness of gonadotropes to GnRH is a primary cause of hypogonadotropic hypogonadism (HH), a disease characterized by gonadal dysfunction and low blood levels of gonadotropins. Loss-of-function mutations in the gene encoding the receptor for GnRH (GNRHR) are a common cause of HH. Sequencing of the GNRHR gene in patients with HH revealed mainly point mutations producing single amino acid substitutions that cause misfolding and misrouting of this G protein-coupled receptor. To generate a mouse model that mimics the human disease, we introduced a single amino acid substitution (E90K) into the mouse Gnrhr gene, which is identical to a known human recessive mutation. In humans, E90K causes severe HH by preventing formation of the E90-K121 salt bridge, which is essential for correct folding. In cell cultures, E90K causes misfolding that leads to almost complete retention by the protein quality control system and subsequent degradation. Here we report that the primary phenotype of mice homozygous for E90K is female infertility due to ovulation failure. Mutant males are fertile despite reduced gonadotropin levels and smaller testes. These results suggest decreased GnRH receptor signaling in the mutant animal, compared with wild type. Our findings suggest that a threshold level of GnRH receptor activity is required for ovulation.
Mol Endocrinol 2012 Nov
PMID:Mice harboring Gnrhr E90K, a mutation that causes protein misfolding and hypogonadotropic hypogonadism in humans, exhibit testis size reduction and ovulation failure. 2291 78

We tested the hypothesis that mutations in NR5A1 and PIN1 cause disorders in gonadotropin-gonadal system development and function, throught direct DNA sequencing of the coding sequence and splice-sites of NR5A1 and PIN1 in 50 subjects with sporadic idiopathic hypogonadotropic hypogonadism. These patients were recruited from the Pediatrics section of Tongji Hospital, Tongji Medical College, in Wuhan, China. None of the affected subjects had clinical signs of adrenal insufficiency. The NR5A1 and PIN1 mutations were found in 7 of the 50 cases. These 7 individuals presented severely low serum concentrations of testosterone or of estradiol and gonadotropin. Adrenal insufficiency was not diagnosed in any of these patients. Consequently, NR5A1 and PIN1 mutations should be considered in idiopathic hypogonadotropic hypogonadism patients with normal karyotypes and without adrenal insufficiency.
Genet Mol Res 2012 Dec 19
PMID:Mutations in NR5A1 and PIN1 associated with idiopathic hypogonadotropic hypogonadism. 2309 8

Genetic studies in human patients with idiopathic hypogonadotropic hypogonadism (IHH) identified mutations in the genes that encode neurokinin B (NKB) and the neurokinin 3 receptor (NK3R). However, determining the mechanism whereby NKB regulates gonadotropin secretion has been difficult because of conflicting results from in vivo studies investigating the luteinizing hormone (LH) response to senktide, a NK3R agonist. NK3R is expressed in a subset of GnRH neurons and in kisspeptin neurons that are known to regulate GnRH secretion. Thus, one potential source of inconsistency is that NKB could produce opposing direct and indirect effects on GnRH secretion. Here, we employ the GT1-7 cell model to elucidate the direct effects of NKB on GnRH neuron function. We find that GT1-7 cells express NK3R and respond to acute senktide treatment with c-Fos induction and increased GnRH secretion. In contrast, long-term senktide treatment decreased GnRH secretion. Next, we focus on the examination of the mechanism underlying the long-term decrease in secretion and determine that senktide treatment represses transcription of GnRH. We further show that this repression of GnRH transcription may involve enhanced c-Fos protein binding at novel activator protein-1 (AP-1) half-sites identified in enhancer 1 and the promoter, as well as chromatin remodeling at the promoter of the GnRH gene. These data indicate that NKB could directly regulate secretion from NK3R-expressing GnRH neurons. Furthermore, whether the response is inhibitory or stimulatory toward GnRH secretion could depend on the history or length of exposure to NKB because of a repressive effect on GnRH transcription.
Mol Endocrinol 2013 Mar
PMID:Neurokinin B causes acute GnRH secretion and repression of GnRH transcription in GT1-7 GnRH neurons. 2339 28

With the advent of improved molecular biology techniques, the genetic basis of an increasing number of reproductive disorders has been elucidated. Mutations in at least 20 genes cause hypogonadotropic hypogonadism including Kallmann syndrome in about 35-40% of patients. The two most commonly involved genes are FGFR1 and CHD7. When combined pituitary hormone deficiency includes hypogonadotropic hypogonadism as a feature, PROP1 mutations are the most common of the six genes involved. For hypergonadotropic hypogonadism, mutations in 14 genes cause gonadal failure in 15% of affected females, most commonly in FMR1. In eugonadal disorders, activating FSHR mutations have been identified for spontaneous ovarian hyperstimulation syndrome; and WNT4 mutations have been described in mullerian aplasia. For other eugonadal disorders, such as endometriosis, polycystic ovary syndrome, and leiomyomata, specific germline gene mutations have not been identified, but some chromosomal regions are associated with the corresponding phenotype. Practical genetic testing is possible to perform in both hypogonadotropic and hypergonadotropic hypogonadism and spontaneous ovarian hyperstimulation syndrome. However, clinical testing for endometriosis, polycystic ovary syndrome, and leiomyomata is not currently practical for the clinician.
Mol Cell Endocrinol 2013 May 06
PMID:The genetic basis of female reproductive disorders: etiology and clinical testing. 2349 66

Inactivating mutations of KISS-1 receptor (KISS1R) have been recently described as a rare cause of isolated hypogonadotropic hypogonadism transmitted as a recessive trait. Few mutations have been described, and the structure-function relationship of KISS1R remains poorly understood. Here, we have taken advantage of the discovery of a novel mutation of KISS1R to characterize the structure and function of an uncommon protein motif composed of 3 proline-arginine-arginine (PRR) repeats located within the intracellular domain. A heterozygous insertion of 1 PRR repeat in-frame with 3 PRR repeats leading to synthesis of a receptor bearing 4 PRR repeats (PRR-KISS1R) was found in the index case. Functional analysis of PRR-KISS1R showed a decrease of the maximal response to kisspeptin stimulation, associated to a lower cell surface expression without modification of total expression. PRR-KISS1R exerts a dominant negative effect on the synthesis of the wild-type (WT)-KISS1R. This effect was due to the nature of inserted residues but also to the difference of the length of the intracellular domain between PRR-KISS1R and WT-KISS1R. A molecular dynamic analysis showed that the additional PRR constrained this arginine-rich region into a polyproline type II helix. Altogether, this study shows that a heterozygous insertion in KISS1R may lead to hypogonadotropic hypogonadism by a dominant negative effect on the WT receptor. An additional PRR repeat into a proline-arginine-rich motif can dramatically changed the conformation of the intracellular domain of KISS1R and its probable interaction with partner proteins.
Mol Endocrinol 2013 Jun
PMID:PRR repeats in the intracellular domain of KISS1R are important for its export to cell membrane. 2360 44


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