Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.1 (RNase)
 16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An in vivo translation system, the Xenopus laevis oocyte, was employed to study the synthesis and secretion of pancreatic proteins. RNA was purified from normal and diabetic rat pancreas and normal rat liver by use of guanidine isothiocyanate lysis and cesium chloride gradient centrifugation. The presence of functional mRNA was documented by translation in a reticulocyte lysate that yielded precursors of all major secretory proteins, i.e., slightly higher Mr than proteins synthesized in situ by pancreatic acini. Mature X. laevis oocytes were then microinjected with either total RNA or purified mRNA. When oocytes were subsequently incubated with 35S-methionine, pancreatic secretory proteins or hepatic albumin could be immunoprecipitated from oocyte lysate with specific polyclonal antibodies against amylase, trypsin, ribonuclease, and albumin. Amylase was shown to be enzymatically active. Moreover, oocytes released pancreatic secretory proteins into the medium when injected with pancreatic RNA in a time-dependent manner. Only the mature form of amylase was secreted and secretion was not regulated by secretagogues. When a comparison was made after injection of RNA from diabetic pancreas known to contain altered amounts of individual mRNAs, there was a decrease in amylase and an increase in trypsinogen synthesis in oocytes that was comparable to the results of cell free translation. The oocyte expression system, therefore, should be useful not only for studies of protein synthesis but also for processing and secretion.
Pancreas 1988
PMID:Synthesis and secretion of rat pancreatic proteins by Xenopus laevis oocytes. 318 82

In order to investigate the role of renal factors in affecting trypsinogen 1 metabolism and excretion in chronic pancreatic disease, serum immunoreactive trypsin (IRT), urinary IRT, gamma-glutamyltransferase (GGT), alpha-glucosidase (AGL) and RNase outputs and the molecular size distribution of serum and urine IRT were studied in 8 control subjects, 18 cases with pancreatic cancer, and 23 cases with chronic pancreatitis. Serum chromatography demonstrated that most immunoreactivity eluted as trypsinogen 1. Smaller amounts of immunoreactivity at higher molecular weights were also observed. Urine chromatography displayed both trypsinogen 1 and heavier molecular forms. An inverse linear correlation was noticed between creatinine clearance and serum trypsinogen 1 levels. Multiple regression analysis (urinary IRT output dependent and GGT, AGL, and RNase predictor variables) showed a significant linear correlation. RNase was found to be the most important parameter in explaining urinary IRT output. Mild variations in the glomerular function seem to be able to influence serum trypsinogen 1 levels. Urinary IRT excretion is principally explained by a disturbance in the tubular reabsorption of low molecular weight proteins, such as RNase.
Pancreas 1988
PMID:Renal factors in serum trypsinogen 1 metabolism and excretion in chronic pancreatic disease. 336 41

In the present study an improved method of reversed-phase high-performance liquid chromatography (HPLC) for separation of rat pancreatic juice proteins is introduced. Aliquots of pancreatic juice were saved from conscious rats during basal secretion. The secretory proteins were separated on a wide-pore silica column by use of a multistep acetonitrile/water gradient. Up to 14 individual peaks could be separated by one run. Molecular weight analysis by sodium dodecyl sulfate (SDS)-gels allowed identification of peaks representing amylase, lipase, procarboxypeptidases, proelastase, chymotrypsinogen, and trypsinogen. Injection of pure rat amylase increased one specific peak which was assumed to represent amylase in the juice profile. Small amounts of residual enzymatic activities were measured for amylase, trypsin, and chymotrypsin in material of certain peaks. Activities of lipase, ribonuclease, and carboxypeptidases were not found, which reflected degradation of these enzymes by the separation procedure. High activities of phospholipase A2 were detected in one specific, early-eluting peak. Reversed-phase HPLC offers precise, reproducible, and rapid separation of the major proteins of rat pancreatic juice.
Pancreas 1988
PMID:Identification of rat pancreatic secretory proteins after separation by high-performance liquid chromatography. 337 29

A pancreas-specific antigen was identified by immunologic techniques and purified from saline extract of human pancreas. The purified pancreas-specific antigen was shown to be homogeneous by polyacrylamide gel electrophoresis under both denaturing and non-denaturing conditions. It had a molecular weight of 44000 as estimated by gel filtration or sodium dodecyl sulfate-gel electrophoresis, and a sedimentation coefficient of 3.4 S as analyzed by sucrose gradient centrifugation. Pancreas-specific antigen possessed an isoelectric point of 4.9 and migrated to alpha-beta region upon immunoelectrophoresis. By colorimetric assay procedures, pancreas-specific antigen exhibited no enzyme activity, such as amylase, protease, esterase, lipase, acid phosphatase, alkaline phosphatase peroxidase, deoxyribonuclease or ribonuclease. Immunoreactivity of pancreas-specific antigen was sensitive to proteolytic enzymes, perchloric acid and high temperature (70 degrees C, 10 min); but insensitive to neuraminidase or beta-glucosidase. Immunohistochemical staining revealed that pancreas-specific antigen was located in acinar cells of human pancreas. In addition, a higher concentration of pancreas-specific antigen was detected in pancreatic juice than in the saline extract of pancreas. This newly identified pancreas-specific antigen, therefore, may be a useful marker protein in physiological studies of pancreas and pancreatic secretion.
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PMID:Purification and characterization of a human pancreas-specific antigen. 678 69

Protein tyrosine phosphatases (PTPs) play important roles in cell growth and differentiation of normal and tumor cells. In this study, we analyzed the PTP profile in two pancreatic islet tumor cell lines. Transcripts were isolated from alphaTC-1 (glucagon-secreting) and betaTC-1 (insulin-secreting) cell lines for templates. A pair of degenerative primers, based on the conserved regions of known PTPs, was used to amplify the transcripts by polymerase chain reaction. A total of 1,620 clones was examined by restriction enzyme analysis and cDNA sequencing. Twenty-one PTPs were identified, including nine cytosolic PTPs (TcPTP, P19PTP, PTP1B, PTPMEG, PTP1C, SYP, PTPH1, PTPL1, and PTPD1), nine transmembrane PTPs (PTPdelta, PTPgamma, PTPkappa, DEP-1, IA-2, LAR, PTPalpha, PTPNE3, and PTPepsilon), and three new PTPs--PTPmu-like PTPkappa-like, and IA-2beta. An RNase protection assay demonstrated that some of these PTPs were expressed predominantly in glucagonoma (i.e., PTPdelta and IA-2) and others in insulinoma (i.e., PTP1C, PTPkappa, and PTPNE3) cells. In this report, we present the first profile of PTPs in alpha and beta tumor cell lines.
Pancreas 1998 May
PMID:Profile and differential expression of protein tyrosine phosphatases in mouse pancreatic islet tumor cell lines. 959 14

A mouse model using repetitive acinar cell injury caused by supraphysiologic doses of cerulein to induce the characteristic fibrosis and loss of acinar cell mass found in human chronic pancreatitis was employed to identify early changes in gene expression. A gene array was used to detect changes in 18,000 expressed sequence tags; changes in specific transcripts were confirmed by RNase protection assays. These methods identified SPINK3, the mouse homologue of human and rat protease inhibitor genes, as being highly expressed in the pancreas and induced after pancreatic injury. Because SPINK3 may be an important serine protease inhibitor, its up-regulation may reflect an important endogenous cytoprotective mechanism in preventing further injury. The up-regulation of SPINK3 was specific; the mouse homologue of the zymogen-processing protein ZG-16p was also highly expressed in the pancreas but sharply down-regulated early in the course of injury. These findings suggest that the pancreatic acinar cell may respond to injury with a program of self-preservation and loss of normal function.
Pancreas 2004 May
PMID:Differential expression of the trypsin inhibitor SPINK3 mRNA and the mouse ortholog of secretory granule protein ZG-16p mRNA in the mouse pancreas after repetitive injury. 1509 71