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)

We have identified a carboxylesterase in A. suum that appears to be the homolog of the gut-specific C. elegans ges-1 enzyme. The A. suum esterase was purified and its N-terminal sequence found to be 50% identical to the C. elegans ges-1 protein. We have used isoelectric focusing analysis to demonstrate that, unlike the C. elegans ges-1 esterase, the A. suum enzyme is not restricted to the gut but is expressed in a wide range of tissues.
Comp Biochem Physiol B Biochem Mol Biol
PMID:A carboxylesterase from the parasitic nematode Ascaris suum homologous to the intestinal-specific ges-1 esterase of Caenorhabditis elegans. 755 43

The 5-hydroxytryptamine3 receptor 5-HT3R has been implicated in gut and cardiac motility and in behavioral disorders. Characteristics of 5-HT3Rs appear to be heterogeneous among species, but human 5-HT3R cDNA has not been identified. We isolated a cDNA encoding 5-HT3R from human hippocampus. The mouse 5-HT3R gene has been reported to generate two alternative splicing isoforms that differ by six amino acids. All of our isolated human clones corresponded to the shorter isoform. Amino acid identities with mouse neuroblastoma N1E-115 and rat brain 5-HT3Rs were 84% for each. Southern blot analysis of human genomic DNA suggested that our cloned transcript encoded a human counterpart for the rodent 5-HT3Rs. This gene was assigned to chromosome 11 using polymerase chain reaction analysis of a human/rodent somatic cell hybrid panel. With the use of Northern blot analysis, 5-HT3R transcripts were identified in human small intestine, colon, and brain regions including hippocampus, amygdala, and striatum. In human heart, 5-HT3R expression was not detectable even with reverse transcriptase-polymerase chain reaction analysis, although it was detectable in mouse heart. Transfection of COS-1 with human 5-HT3R cDNA induced specific binding of the 5-HT3R-selective radioligand [3H]YM060. Human 5-HT3R showed typical characteristics of the 5-HT3R, but its affinity for the 5-HT3R agonist m-chlorophenylbiguanide was much lower than that of rat 5-HT3R. When injected with human 5-HT3R cRNA, the oocytes responded to 5-HT3R agonists with a rapidly developing inward current. The potency of the agonists to induce inward current paralleled that to compete with the radioligand binding, and 2-methyl-5-hydroxytryptamine, a partial agonist for mouse 5-HT3R, was a full agonist for human 5-HT3R. Our data revealed that the 5-HT3R molecule has interspecies differences in both tissue distribution and functional profile.
Mol Pharmacol 1995 Sep
PMID:Molecular cloning of human 5-hydroxytryptamine3 receptor: heterogeneity in distribution and function among species. 756 20

Ectopic ACTH syndrome represents a cancer-induced amplification of a property [proopiomelanocortin (POMC) peptides production] normally present in the cells from which the cancer originated but with aberrant posttranslational processing of POMC resulting in a greatly elevated secretion of ACTH precursors. The classic ectopic ACTH-producing tumors described in the 1960s were highly malignant but more recently slowly growing tumors such as carcinoids are reported with increasing frequency. Clinical features of patients with ectopic ACTH were analyzed, including biochemical abnormalities, plasma ACTH, cortisol and urinary steroids. Dynamic tests such as high-dose dexamethasone suppression, metyrapone and ovine-CRH (oCRH) stimulation were explored, as well as inferior petrosal sinus ACTH sampling before and after oCRH. Among the tumor markers examined, elevation of ACTH precursors was uniformly present followed by increased output of calcitonin, gut hormones, oncofetal and placental hormones in decreasing order. Since more than 90% of ectopic ACTH tumors are neuroendocrine in nature exhibiting APUD characteristics, their 2 markers, neuron-specific enolase and chromogranins are very useful. The imaging procedures for localization of the tumor ranged from chest X-rays to computed tomography and magnetic resonance of the chest and abdomen. Abdominal ultrasonography was also useful. Finally somatostatin receptor scintigraphy permitted demonstration of unrecognized tumors and/or metastases, even when the tumors were occult. The ACTH content, immunostaining for APUD markers and altered POMC processing were evaluated in ectopic tumors and/or metastases. Occult ectopic ACTH syndrome of more than 4-6 months of symptoms without the emergence of an obvious source was reviewed. Since the tumors are often clinically and biochemically undistinguishable from pituitary-dependent Cushing's disease, inferior petrosal sinus sampling for ACTH after oCRH stimulation established the diagnosis in over 90% of the cases. 60% of the occult tumors were thoracic carcinoids (3/4 bronchial carcinoids), followed by small cell lung cancer and pancreatic neuroendocrine tumors. In 12% the primary etiology was not detected. The rare syndrome of ectopic CRH syndrome (6 published cases) leading to excessive stimulation of the pituitary which became hyperplastic and secreted excessive amounts of ACTH is discussed. Finally, the 12 published cases and 1 unreported patient with ectopic CRH-ACTH tumors were reviewed, the majority being metastatic small cell lung carcinomas, bronchial and thymic carcinoids.
J Steroid Biochem Mol Biol 1995 Jun
PMID:Ectopic ACTH syndrome. 762 46

The sequences of two folliculostatic peptides of the fleshfly Neobellieria bullata have been determined recently. The first peptide (Neb-TMOF: H-NPTNLH-OH), originates from a 75 kDa precursor protein found in vitellogenic oocytes. The hexapeptide directly inhibits the synthesis of trypsin-like enzymes in the gut, and thus lowers the concentration of yolk polypeptides in the hemolymph. It also inhibits the biosynthesis of ecdysone in the larval ring gland. Therefore, it could also be named prothoracicostatic hormone (Neb-PTSH). The second peptide (Neb-colloostatin: H-SIV-PLGLPVPIGPIVVGPR-OH) acts on previtellogenic follicles and is a cleaved product of a collagen-like precursor molecule. Our results indicate that peptides that are cleaved from matrix proteins could act as growth-inhibiting factors. Gonadotropin releasing hormone (GnRH)-immunolike peptides were not identified, but progress is being made in the isolation and characterization of factors which stimulate cAMP production by the ovary. Using these results, a novel model of growth control in which matrix proteins play an important role as a potential source of growth regulators has been developed.
Insect Biochem Mol Biol 1995 Jun
PMID:Folliculostatins, gonadotropins and a model for control of growth in the grey fleshfly, Neobellieria (sarcophaga) bullata. 762 97

Manduca sexta larvae that are parasitized by the braconid wasp Cotesia congregata enter a state of developmental arrest following emergence of the wasp larvae from the host. These fifth instar hosts linger for 2 to 3 weeks without resuming feeding, molting, or metamorphosis once the wasps emerge. Immunohistochemical staining with antiserum against FMRFamide revealed dramatic accumulation of FMRFamide-like peptide(s) in the gut nervous and endocrine systems of the developmentally arrested larvae when compared to that observed in unparasitized feeding or starved larvae. Specifically, the number of immunopositive cells and the intensity of staining was enhanced in the neurons of the frontal ganglion, the axons and axon terminals on the midgut surface, and in the gastric endocrine cells. These results were confirmed using ELISA to show that the relative amounts of FMRFamide-like peptides in midgut extracts were highly elevated in the parasitized larvae relative to the fed or starved unparasitized larvae. These data suggest that FMRFamide-like peptides in developmentally arrested larvae are produced in a significantly larger number of gastric endocrine cells, and that the rate of release of the peptides may be suppressed, or the rate of their synthesis may be elevated. Localization of FMRFamide-like peptides in the gastric endocrine cells of C. congregata is also described.
Insect Biochem Mol Biol 1995 Jun
PMID:Parasitism-induced accumulation of FMRFamide-like peptides in the gut innervation and endocrine cells of Manduca sexta. 762 99

Hirschsprung disease (HSCR), or congenital aganglionic megacolon, is the most common cause of congenital bowel obstruction with an incidence of 1 in 5000 live births. Recently, linkage of an incompletely penetrant, dominant form of HSCR was reported, followed by identification of mutations in the RET receptor tyrosine kinase. To determine the frequency of RET mutations in HSCR and correlate genotype with phenotype, we have screened for mutations among 80 HSCR probands representing a wide range of phenotypes and family structures. Polymerase chain reaction (PCR) and single-strand conformation polymorphism (SSCP) analysis of RET's 20 exons for mutations among probands revealed eight putative mutations (10%). Sequence changes, which included missense, frameshift and complex mutations, were detected in both familial and isolated cases, among patients with both long- and short-segment HSCR and in three kindreds with other phenotypes (maternal deafness, talipes and malrotation of the gut, respectively). Two mutations (C609Y and C620R) we identified have previously been associated with multiple endocrine neoplasia type 2A (MEN2A), medullary thyroid carcinoma (MTC) and, on rare occasions, HSCR. Thus, while HSCR family members may be at risk for developing neuroendocrine tumors, it follows that identical mutations in RET may be able to participate in the pathogenesis of distinct phenotypes. Our data suggest that: (i) the overall frequency of RET mutations in HSCR patients is low and therefore, other genetic and/or environmental determinants contribute to the majority of HSCR susceptibility, and (ii) at present, there is no obvious relationship between RET genotype and HSCR phenotype.
Hum Mol Genet 1995 May
PMID:Mutation analysis of the RET receptor tyrosine kinase in Hirschsprung disease. 763 41

A 1194 bp open reading frame that codes for a 398 amino acid peptide was cloned from a lambda gt11 library of Drosophila melanogaster genomic DNA. The predicted peptide sequence is very similar to three previously characterized protein sequences that are encoded by the ftsZ genes in Escherichia coli, Bacillus subtilis and Rhizobium meliloti. The FtsZ protein has a major role in the initiation of cell division in prokaryotic cells. Using a tetracycline treatment that eradicates bacterial parasites from insects, the ftsZ homologue has been found to be derived from a bacterium that lives within the D. melanogaster strain. However, polymerase chain reaction (PCR) amplification of the gene from treated embryos suggests that it is not derived from a gut bacterium. Nevertheless, by amplifying and characterizing part of the 16S rRNA from this bacterium we have been able to demonstrate that it is a member of the genus Wolbachia, a parasitic organism that infects, and disturbs the sexual cycle of various strains of Drosophila simulans. We suggest that this ftsZ homologue is implicated in the cell division of Wolbachia, an organism that fails to grow outside the host organism. Sequence and alignment analysis of this ftsZ homologue show the presence of a potential GTP-binding motif indicating that it may function as a GTPase. The consequences of this function particularly with respect to its role in cell division are discussed.
Mol Gen Genet 1993 Aug
PMID:Cloning and characterization of an ftsZ homologue from a bacterial symbiont of Drosophila melanogaster. 768 40

The metabolism of [U-14C]isoleucine was examined in different tissues of five species of lepidopteran and four species of non-lepidopteran insects. Slices of fat body, epidermis, Malpighian tubule, gut, and muscle were incubated in a culture medium containing [U-14C]isoleucine; the medium was analyzed by ion-exclusion LC to quantify labeled metabolites. Tissues of lepidopteran insects secrete high levels of metabolites including 2-keto-4-methylvalerate, 2-methylbutyrate, propionate, and acetate. Tissues of non-lepidopteran insects secrete low amounts of these acids. Analysis of isoleucine transaminase activity in selected tissues of non-lepidopteran insects indicated that those tested contain significant activity. These results demonstrate that tissues of lepidopteran insects have a unique ability to secrete short chain acids, derived from isoleucine, into the medium. The secretion of propionate correlates with the ability to synthesize ethyl-branched juvenile hormones and indicates the presence of an efficient transport system for short chain acids. We also monitored the secretion of acidic metabolites of isoleucine by different tissues of the rat. Muscle was most active in secreting keto acid whereas heart secreted high levels of 2-methylbutyrate. Negligible quantities of metabolites of isoleucine were secreted by the liver.
Comp Biochem Physiol B Biochem Mol Biol 1995 Feb
PMID:A comparative catabolism study of isoleucine by insect and mammalian tissues. 771 44

Sequestration of the blue biliprotein, insecticyanin, into developing oocytes of the hawkmoth, Manduca sexta was investigated. Immunodiffusion assays revealed that insecticyanin concentration in mature eggs (29.6 microM) is slightly higher than that in hemolymph (25.8 microM). The endocytotic uptake of insecticyanin was visualized at the light microscopic level using autoradiography. Uptake of 125I-insecticyanin by isolated oocytes was saturable. Analysis of in vitro uptake data estimated that the value of K(uptake) (insecticyanin concentration at half-maximal uptake rate) is 4.2 microM and that the Vmax (maximum rate of uptake) is 1 pmol follicle-1 h-1. Labeled insecticyanin was shown to bind to sonicated follicle membranes with high specificity and affinity. The KD (equilibrium dissociation constant) and the Bm (total number of binding sites per follicle), were estimated as 4 x 10(-8) M and 8 x 10(7) respectively. Competition studies showed that binding of labeled insecticyanin to oocyte membranes was blocked by excess amounts of unlabeled insecticyanin but not by lipophorin and vitellogenin of M. sexta. Additional membrane binding experiments demonstrated that receptors for insecticyanin are only present in the oocytes membranes, not in fat body or gut tissue.
Insect Biochem Mol Biol 1995 Apr
PMID:Sequestration of insecticyanin, a blue hemolymph protein, into the egg of the hawkmoth Manduca sexta. Evidence for receptor-mediated endocytosis. 774 35

Tsetse flies (Diptera: Glossinidae) harbour two morphologically different endosymbionts intracellularly associated with gut tissue: a primary (P) and a secondary (S) organism. The P-endosymbiont is a gram-negative rod, 8-10 microns in size, and resides intracellularly within specialized cells, mycetocytes which are organized into an organelle (mycetome), in the anterior portion of the gut. The S-endosymbiont is a smaller (1-2 microns) gram-negative rod and is harboured in the epithelial sheath cells in midgut. Phylogenetic characterization of S-endosymbionts from taxonomically distant insects including tsetse flies has shown that they are related to the free-living bacterium, Escherichia coli, and are members of the family Enterobacteriaceae within the gamma-3 subdivision of Proteobacteria. In this study, a polymerase chain reaction (PCR) based assay was designed utilizing the conserved sequences of 16S rDNA in order to phylogenetically characterize the mycetome-associated P-endosymbionts directly from tsetse mycetome tissue. Analysis from five species of flies representing the three major subgenera of genus Glossina indicates that P-endosymbionts constitute a distinct lineage within the gamma-3 subdivision of Proteobacteria. Mycetome endosymbiont phylogeny appears to parallel the classic taxonomic assignments independently developed for their insect host species. This suggests an ancient association for this symbiosis, which may have subsequently radiated with time, giving rise to the current species of tsetse flies and their modern-day endosymbionts. Based on endosymbiont phylogeny, the fusca flies constitute the most ancient subgenus, followed by the morsitans and palpalis groups.
Insect Mol Biol 1995 Feb
PMID:Mycetome endosymbionts of tsetse flies constitute a distinct lineage related to Enterobacteriaceae. 774 73


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