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)

Human urinary Tamm-Horsfall glycoprotein, which contains 28% carbohydrate, has a monomeric molecular weight of about 80,000 but is isolated from urine in the form of intertwining helical suprastructures with molecular weights greater than 10(7). The native glycoprotein was dissociated and denatured with 6 M guanidinium chloride and was subsequently renatured by dialysis against a Tris-HCl buffer. Using sedimetation equilibrium, the renatured glycoprotein was characterized by a Mw cell of 256,800 and a Mz cell of 356,000. The ratio, Mz/Mw, of 1.39 indicates some polydispersity with regard to molecular size. There was no evidence of helical suprastructures in the renatured glycoprotein as judged by electron microscopy. Ca2+ concentrations of up to 50 mM failed to precipitate the renatured glycoprotein; in contrast, the native glycoprotein is precipitated by Ca2+ concentrations between 5-10 mM. The circular dichroic spectrum of renatured Tamm-Horsfall glycoprotein was obtained, resolved, and tentative band assignments made. The spectrum, which is quite similar to that of native Tamm-Horsfall glycoprotein, exhibited negative extrema at 269 nm (due in large part to disulfides and tyrosines) and at 215 nm (due to protein beta-structure and the N-acetylated hexosamines). The alpha-helical content of the glycoprotein was estimated to be no more than 10% and the amount of beta-structure to be about 33%; these values were not affected by the presence of Ca2+ (1 mM). A glcopeptide fraction (ca. 90% carbohydrate), prepared by extensive pronase digestion of the reduced, S-carboxymethylated glycoprotein, exhibited an ellipticity extremum at 212 nm of + 4,750 deg-cm2/dmole, referred to the concentration of (N-acetylated) hexosamines and neuraminic acid.
Mol Cell Biochem 1977 Apr 12
PMID:Circular dichroism of human urinary Tamm-Horsfall glycoprotein. 89 29

Trypsin dissociated intact cells of embryonic chick liver catalyze the transfer of mannose from exogenous GDP-mannose to glycoprotein in vitro. In cells of 8 day old embryos a surface bound mannosyltransferase-system forms several mannose containing isoprenoid-lipids in a primary step. One of these compounds serves as a substrate in the highly specific second step of the overall reaction, the transfer of mannose to glycoprotein. The isoprenoic intermediate has been isolated and its effectivity as substrate for the incorporation of mannose into glycoprotein has been examined.
Mol Cell Biochem 1976 Jun 15
PMID:Cell surface mannosyl transferase activity in the liver of embryonic chick. A mannose containing glycolipid as intermediate in glycoprotein synthesis. 94 63

(1) Preparative dodecyl sulfate gel electrophoresis of human erythrocyte membrane proteins has been used to isolate dodecylsulfate band 3 containing the M,N-glycoprotein and the major "intrinsic" membrane protein (Fairbanks, G., Steck, T.L. and Wallach, D.F.H. (1971) Biochemistry 10, 2606-2617; Bretscher, M.S. (1971) J. Mol. Biol. 59,351-357; Bretscher, M.S. (1971) Nat. New Biol. 231, 229-232 and Marchesi, V.T. and Andrews, E.P. (1972) Science 174, 1247-1248). Subsequent isoelectric focusing in polyacrylamide gels containing Triton X-100 separates these two entities and allows their simultaneous purification. (2) The proteins thus obtained retain their antigenic properties. They are pure according to electrophoretic and immunoelectrophoretic criteria. However, crossed immunoelectrophoresis yields evidence for molecular microheterogeneity of the major "intrinsic" protein. (3) Analyses utilizing crossed immunoelectrophoresis with antibodies absorbed with intact erythrocytes show that the major "intrinsic" protein possesses antigenic determinants on both membrane surfaces and therefore spans the erythrocyte membrane. All determinants of the M,N-glycoprotein detectable with our antibodies were found solely on the exterior membrane surface. (4) Neither the major "intrinsic" membrane protein nor the major M,N-glycoprotein bound significantly to concanavalin A in crossed immunoaffinoelectrophoresis.
 ...
PMID:The major "intrinsic" membrane protein of human erythrocytes. Preparative isolation and immunoelectrophoretic analyses. 99 Feb 85

Plasma glycoprotein synthesis in the liver occurs in a stepwise fashion. The first sugar, N-acetyl-glucosamine, is attached to the protein during the growth of the polypeptide chain on the membrane-bound ribosomes. Subsequent carbohydrates are incorporated after the completion of the protein in the lumen of the endoplasmic reticulum and Golgi apparatus. The reactions are carried out by enzymes strongly bound to the membranes. Because the glycosylation reaction occurs in the interior of the cytoplasmic tubules a permeability problem for the nucleotide sugar exists. Recent studies indicate that sugar-lipids are formed on the cytoplasmic site of the membrane and these complexes transfer the sugars across the membrane. Experimental evidence for this pathway is presented in this article.
Mol Cell Biochem 1975 Jan 31
PMID:A proposed pathway of plasma glycoprotein synthesis. 112 82

The insoluble collagen from methylcholanthrene induced sarcoma was isolated and characterized. It contains more glycine, hydroxyproline and acidic amino acids than normal connective tissue collagen. An anionic character of tumour collagen was stated (pI 6.1). No typical collagen subunits in this protein were found. The tumour collagen is strongly bound to acidic glycoprotein containing a significant amount of hydroxylysine. Such an insoluble complex is resistant to the dispersing action of EDTA. It dissociates during heating in concentrated urea.
Mol Cell Biochem 1975 Jul 31
PMID:Insoluble collagen of methylcholanthrene induced sarcoma. 117 75

Testicular androgen binding protein (ABP) was purified from the epididymis of 1500 adult rabbits by the sequential use of ammonium sulphate precipitation, ion exchange chromatography on DEAE cellulose, gel filtration on Sephadex G-200, hydroxyl-apatite chromatography and preparative polyacrylamide gel electrophoresis. This procedure yielded a 1000-fold increase in specific activity compared to that of the 1500,000 x g supernatant, and the recovery of active ABP was about 3-5%. ABP is acid glycoprotein with a molecular weight of 65-68,000 daltons. Antisera to rabbit ABP raised in quinea pigs inhibit 3H-DHT binding to ABP as measured by SS-PAGE. When diluted rabbit serum containing TeBG is treated with the same dilutions of these antisera, identical binding inhibition curves are found. Thus, ABP and TeBG in rabbits appear to possess identical immunological determinants.
Curr Top Mol Endocrinol 1975
PMID:Purification and characterization of rabbit testicular androgen binding protein (ABP). 124 82

Sulfated glycoprotein-2 (SGP-2) is emerging as a prominent marker of neurodegeneration in mammalian brain. Regulation of brain SGP-2 was studied in adult male Wistar rats subjected to 30 min of forebrain ischemia by four vessel occlusion. By 3 days after the ischemic insult, SGP-2 RNA levels were increased two fold in caudate nucleus and hippocampus. SGP-2 protein levels assessed by immunoblots were markedly increased in both brain regions following ischemia. GFAP RNA levels also increased over 5 fold in caudate nucleus and hippocampus following the ischemic insult. Despite significant elevations in GFAP RNA, protein levels of GFAP assessed by immunoblot were only marginally affected. The elevated expression of SGP-2 in rodent brain following this and other experimental lesion paradigms (e.g., excitotoxic lesions, deafferentation) suggest some general involvement of SGP-2 in neurodegeneration and remodelling following neuronal injury.
Brain Res Mol Brain Res 1992 Sep
PMID:Sulfated glycoprotein-2 expression increases in rodent brain after transient global ischemia. 127 48

The proximal 5'-flanking region of the alpha-subunit gene from humans and cattle confers pituitary-specific expression to heterologous reporter genes in transgenic mice. To investigate whether these promoter regions also contain the necessary regulatory elements for cell-specific expression and hormonal regulation, we used three independent lines of transgenic mice. Two lines of transgenic mice contained chimeric genes consisting of either 1.6 kilobasepairs (kbp) of human or 3 15 basepairs of bovine alpha-subunit proximal 5'-flanking sequence linked to the bacterial gene encoding chloramphenicol acetyltransferase (CAT). A third line of transgenic mice contained the proximal 1.6 kbp of 5'-flanking sequence of the human alpha-subunit gene linked to the bacterial lacZ gene encoding beta-galactosidase (beta gal; H alpha beta gal transgenic mice). Hormonal replacement paradigms indicate that both human and bovine alpha CAT transgenes are regulated by GnRH, suggesting that their expression occurs in gonadotropes. Thus, the proximal 5'-flanking regions of both the human and bovine alpha-subunit genes must contain regulatory elements that confer both gonadotrope-specific expression and responsiveness to GnRH. In contrast to the human alpha-subunit promoter, the bovine alpha-subunit promoter lacks a functional cAMP response element, suggesting that transduction of both cell-specific and GnRH transcriptional signals occurs through cAMP response element-independent pathways. Thyrotropes also express the glycoprotein hormone alpha-subunit gene. Yet, hormone replacement paradigms with propylthiouracil and T3 were ineffective in altering CAT activity in the pituitary of human or bovine alpha CAT transgenic mice. Because a thyroid hormone response element has been localized to the proximal 5'-flanking region of the human alpha-subunit gene, these data suggest that the alpha CAT transgenes lack sufficient information to direct expression to thyrotropes. Direct evidence for this possibility was obtained through immunocytochemical studies performed on pituitaries from H alpha beta gal transgenic mice. beta-Galactosidase activity appeared in gonadotropes, but not thyrotropes. We conclude, therefore, that distinct and separable regulatory elements mediate the expression of the alpha-subunit gene in gonadotropes and thyrotropes.
Mol Endocrinol 1992 Oct
PMID:Gonadotrope- and thyrotrope-specific expression of the human and bovine glycoprotein hormone alpha-subunit genes is regulated by distinct cis-acting elements. 128 Mar 29

The glycoprotein gp210 is located in the "pore membrane," a specialized domain of the nuclear envelope to which the nuclear pore complex (NPC) is anchored. gp210 contains a large cisternal domain, a single transmembrane segment (TM), and a COOH-terminal, 58-amino acid residue cytoplasmic tail (CT) (Wozniak, R. W., E. Bartnik, and G. Blobel. 1989. J. Cell Biol. 108:2083-2092; Greber, U. F., A. Senior, and L. Gerace. 1990. EMBO (Eur. Mol. Biol. Organ.) J. 9:1495-1502). To locate determinants for sorting of gp210 to the pore membrane, we constructed various cDNAs coding for wild-type, mutant, and chimeric gp210, and monitored localization of the expressed protein in 3T3 cells by immunofluorescence microscopy using appropriate antibodies. The large cisternal domain of gp210 (95% of its mass) did not reveal any sorting determinants. Surprisingly, the TM of gp210 is sufficient for sorting to the pore membrane. The CT also contains a sorting determinant, but it is weaker than that of the TM. We propose specific lateral association of the transmembrane helices of two proteins to yield either a gp210 homodimer or a heterodimer of gp210 and another protein. The cytoplasmically oriented tails of these dimers may bind cooperatively to the adjacent NPCs. In addition, we demonstrate that gp210 co-localizes with cytoplasmically dispersed nucleoporins, suggesting a cytoplasmic association of these components.
 ...
PMID:The single transmembrane segment of gp210 is sufficient for sorting to the pore membrane domain of the nuclear envelope. 128 15

Transcriptional regulation of the glycoprotein hormone alpha-subunit gene has been studied extensively in placental cells, but much less is known about its regulation in the pituitary gland. In this study, transcriptional control of the human alpha-subunit gene by GnRH was analyzed using transient expression assays in primary cultures of rat pituitary cells using alpha promoter constructs linked to a luciferase reporter gene. Deletion mutants between -846 and -156 basepairs (bp) had little effect on basal expression, but further deletion to -132 bp reduced basal activity by approximately 50%. Deletion of a cAMP response element between -132 and -99 bp caused a marked loss of basal activity, reducing expression to that of background luciferase activity. The same constructs were analyzed for cAMP responsiveness in primary pituitary cells. The degree of stimulation with 1 mM 8-bromo-cAMP (3.6- to 6.0-fold) was relatively unaffected by deletions from -846 to -132 bp, whereas cAMP stimulation was decreased by further deletion to -99 bp, consistent with the presence of previously defined cAMP response elements in this region of the alpha promoter. GnRH stimulation of alpha promoter activity was highly dependent upon the time of hormone addition after transfection, being most effective when added soon after transfection. Under optimal conditions, GnRH stimulated -846 alpha LUC expression by 20-fold. GnRH responsiveness was retained with deletion to -346 bp, but it was decreased by 55% after deletion to -280 bp and by 79% with deletion to -244 bp.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1992 Nov
PMID:Identification of a gonadotropin-releasing hormone-responsive region in the glycoprotein hormone alpha-subunit promoter. 128 68


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