Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prion diseases are believed to develop from the conformational change of normal cellular prion protein (PrPc) to a pathogenic isoform (PrPsc). PrPc is present in both the central nervous system and many peripheral tissues, although protein concentration is significantly lower in non-neuronal tissues. PrPc expression is essential for internalization and replication of the infectious agent. Several works have pointed to the gastrointestinal (GI) tract as the principal site of entry of PrPsc, but how passage through the GI mucosa occurs is not yet known. Here we studied PrPc expression using Western blot, RT-PCR, and immunohistochemistry in rat GI tract. PrPc mRNA and protein were detected in corpus, antrum, duodenum, and colon. Immunoreactivity was found in scattered cells of the GI epithelium. With double immunofluorescence, these cells have been identified as neuroendocrine cells. PrPc immunostaining was found in subsets of histamine, somatostatin (Som), ghrelin, gastrin (G), and serotonin (5HT) cells in stomach. In small and large bowel, PrPc cells co-localized with subpopulations of 5HT-, Som-, G-, and peptide YY-immunolabeled cells. Our results provide evidence for a possible and important role of endocrine cells in the internalization of PrPsc from gut lumen.
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PMID:Cellular prion protein is expressed in a subset of neuroendocrine cells of the rat gastrointestinal tract. 1538 82

The gastrointestinal tract (GIT) is one of the most likely entry sites for the pathological isoform of prions (PrP(sc)). To understand how PrP(sc) crosses the digestive mucosa, it is crucial to characterize the cells expressing normal prion protein (PrP(c)). By means of double immunofluorescence applied to sections of the monkey GIT, we demonstrated that, in the stomach, PrP(c) immunostaining occurs in subsets of histamine, somatostatin (Som), ghrelin (Ghr), gastrin (G), and serotonin (5HT) cells. In the small and large bowels, PrP(c) cells were found in subpopulations of cells immunolabeled for 5HT, Som, G, and peptide YY (PYY).
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PMID:Characterization of PrPc-immunoreactive cells in monkey (Macaca fascicularis) gastrointestinal tract. 1589 Oct 69

Expression of the cellular prion protein (PrP(c)) has been shown to be crucial for the development of transmissible spongiform encephalopathies and for the accumulation of the disease-associated conformer (PrP(sc)) in the brain and other tissues. One of the emerging hypotheses is that the conversion phenomenon could take place at the site where the infectious agent meets PrP(c). In this work we have studied whether PrP(c), a protein found predominantly in neurons, could also exist in pancreatic endocrine cells since neuroectoderm-derived cells and pancreatic islet cells share a large number of similarities. For this purpose we have examined the expression of PrP(c) in a series of fetal and postnatal bovine pancreatic tissue by immunohistochemistry and RT-PCR. Using immunostained serial sections and specific antibodies against bovine PrP(c), insulin, glucagon, somatostatin, chromogranin A and chromogranin B we found that PrP(c) is highly expressed in all endocrine cells of fetal and adult pancreatic islets with a particular strong expression in A-cells. Moreover it became evident that the PrP(c) gene-neighbour chromogranin B as well as chromogranin A are coexpressed together with PrP(c). The selective expression of PrP(c) in the bovine endocrine pancreas is of particular importance regarding possible iatrogenic transmission routes and demonstrates also that bovine pancreatic islet cells could represent an interesting model to study the control of PrP-gene expression.
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PMID:The normal cellular prion protein (PrPc) is strongly expressed in bovine endocrine pancreas. 1620 84

Membrane protein function is determined by the relative organization of the protein domains with respect to the membrane. We have experimentally verified the topology of a protein with diverse orientations arising from a single primary sequence (the cellular prion protein, PrP(C)), a novel somatostatin truncated receptor, and the Golgi-associated protein GPBP(91). Tagging with fluorescent proteins (FP) allows location of their expression at the plasma membrane or at endomembranes, but does not inform about their orientation. Exploiting the pH dependency of some FPs, we developed a pH exchange assay in which extracellularly exposed FPs are quenched by application of low pH buffer. We constructed standards to demonstrate and calibrate the assay, and the method was adapted for acidic organelle membrane proteins. This method can serve as a proof of concept, experimentally confirming and/or discriminating in living cells among theoretical topology predictions, providing the proportion of inside/outside orientation for proteins with multiple forms.
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PMID:Discrimination between alternate membrane protein topologies in living cells using GFP/YFP tagging and pH exchange. 2045 16