Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of glucose on the androgen-maintained protein synthesis was studied in the cultured rat ventral prostate. The explants were cultivated for 5 days in the glucose-free medium containing 10% fetal calf serum with or without 10 mM glucose and 10(-7) M testosterone. In some experiments tunicamycin, a specific inhibitor of protein glycosylation was added to the glucose-containing medium. The morphological integrity of the tissue was maintained in all the mediums used. At the end of the culture, the explants were incubated with [35S]methionine. Soluble radioactive proteins were separated by the SDS-polyacrylamide gel electrophoresis and analyzed further by the fluorography. Glucose was necessary for the testosterone-maintained accumulation of three components (Mr less than 14,000) of the major prostatic secretory protein. The electrophoretic migration, glycosylation pattern and immunological data (not shown) indicated that it was the well-known prostatic binding protein. On the other hand, two prominent polypeptides (Mr 70,000 and 100,000) appeared in the absence of glucose. Glucose starvation and the inhibition of glycosylation with tunicamycin caused similar effects on the labelling of the newly-synthesized soluble proteins. The mechanisms of glucose maintenance of the major prostatic protein and suppression of two high molecular weight proteins seemed to be different, although glycosylation was probably involved in both glucose effects.
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PMID:Effect of glucose on the major testosterone-maintained protein in the cultured rat ventral prostate. 670 32

The differentiation of starving Physarum polycephalum microplasmodia into resting structures (spherules) was studied. Early events in this differentiation pathway include decreases in both plasmodial motility and protein synthesis. The starving plasmodia show a blue light avoidance response. Blue light (lambda max 450 nm, irradiance 16 W/m2) acts antagonistically to the starvation stimulus so that spherule formation is inhibited [16]. Light affects each of the above mentioned events of the differentiation pathway: the migration rate of illuminated plasmodia is stimulated, the light avoidance response is irreversibly lost. The rate of incorporation of radioactive leucine into plasmodial protein remains at a higher level in illuminated plasmodia as compared to the decreasing rate during spherule formation in the dark. Protein degradation, uptake of external leucine, and the size of the internal leucine pool are not affected by light. Analysis by SDS-polyacrylamide gel electrophoresis of pulse-labelled plasmodial proteins reveals that blue light inhibits the synthesis of distinct starvation-induced proteins and allows continued synthesis of all major plasmodial proteins. Some of the blue light responses described are mimicked by alpha-amanitin suggesting that light might influence gene expression at the level of transcription.
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PMID:Blue light influences gene expression and motility in starving microplasmodia of Physarum polycephalum. 712 14

Lipoprotein lipase (EC 3.1.1.34) extracted from adipose tissue of glucose-fed rats with 5 mM-sodium barbital, pH 7.5, containing 20% (v/v) glycerol and 0.1% (v/v) Triton X-100, was partially purified by affinity chromatography on heparin linked to Sepharose 4B. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of the partially purified enzyme preparation revealed the presence of two major Coomassie-staining bands (mol.wts. 62 000 and 56 000) as well as a number of minor bands. Treatment of partially purified enzyme with [1,3-3H]di-isopropyl fluorophosphate resulted in the incorporation of radiolabel into the band of mol.wt. 56 000, but not into the band of mol.wt. 62 000. Both the amount of the 56 000-mol.wt. polypeptide and the incorporation of [1,3-3H]di-isopropyl fluorophosphate into this band were greatly reduced in the enzyme preparations isolated from adipose tissue of 48 h-starved rats. whereas the amount of the 62 000-mol.wt. polypeptide was unaffected by starvation. Purification of lipoprotein lipase from adipose tissue of glucose-fed rats was also carried out using affinity chromatography on Sepharose 4B linked to heparin with low affinity for antithrombin-III. This procedure resulted in the presence of a single band of mol.wt. 56 000 on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. These results suggest that the polypeptide of mol.wt. 56 000 corresponds to the subunit of lipoprotein lipase, whereas the 62 000-mol.wt. polypeptide probably represents antithrombin-III.
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PMID:Purification and characterization of rat adipose tissue lipoprotein lipase. 716 5

The IGF regulatory system has been shown to mediate mitogenic effects during normal growth and tumor proliferation. The bioavailability of both IGF-I and IGF-II is regulated by at least six specific IGF binding proteins (IGFBPs). Whereas IGFBP-3 is the main IGFBP postnatally, IGFBP-2 is the predominant IGFBP during fetal life. In addition, IGFBP-2 is expressed in a range of tumor cell lines. In order to investigate the IGF regulatory pathway in malignancies we analyzed by RIA serum samples of 49 children with leukemia, Non-Hodgkins' Lymphoma (NHL) or solid tumors at the time of diagnosis. Serum concentrations of IGF-I (mean/range: -2.4/0.3 to -9.9 SDS), IGF-II (-2.5/0.2 to -5.6 SDS) and IGFBP-3 (-1.3/2.2 to -6.8 SDS) were significantly decreased, but IGFBP-2 (3.2/-0.9 to 8.6 SDS) was elevated. Both absolute as well as SDS values of IGF-I, -II and the sum of IGF-I and IGF-II (r = -0.49, p < 0.01) were inversely correlated with IGFBP-2. Serum levels of the growth factors IGF-I and IGF-II were significantly decreased in different types of malignancies to concentrations usually seen only in patients with growth hormone deficiency or during starvation. However, the elevated levels of IGFBP-2 in 70% of our patients exceeded by far those in growth hormone deficiency. Furthermore, in this study we could demonstrate that serum levels of IGF-I and IGF-II were inversely correlated to IGFBP-2 independent on the type of malignancy, indicating a common regulatory mechanism of the IGF signaling pathway in these diseases.
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PMID:[Serum concentrations of insulin-like growth factors (IGF)-I and IGF-II and IGF binding proteins (IGFBP)-2 and IGFBP-3 in 49 children with ALL, NHL or solid tumors]. 756 58

The DNA sequence upstream of the dhlB gene encoding the haloalkanoic acid dehalogenase of Xanthobacter autotrophicus GJ10 was determined and contained an open reading frame, designated dhlC, which encoded a protein with a significant similarity with the family of Na(+)-dependent symport proteins. The dhlC gene was subcloned under control of a T7 promoter, and found to encode a polypeptide of 45 kDa on SDS-PAGE. Upstream of dhlC, a -24/-12 promoter sequence was found. Further upstream, in the opposite direction of transcription, another open reading frame, designated dhlR, with homology with the family of sigma 54-dependent transcriptional activator proteins was detected. The dhlR gene was cloned and expressed under the control of a T7 promoter and encoded a polypeptide of 51 kDa on SDS-PAGE. The genetic organization of the dhlB region suggested that the expression of dhlC and dhlB was controlled by the product of dhlR and sigma 54 which may explain the observed overexpression of the haloalkanoic acid dehalogenase under starvation conditions.
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PMID:Sequence analysis of the upstream region of dhlB, the gene encoding haloalkanoic acid dehalogenase of Xanthobacter autotrophicus GJ10. 758

During starvation muscle protein degradation is increased but the mechanism for this is uncertain. In this study Japanese quail were starved for 5 days and the activities of malic enzyme and acetylcholinesterase were determined in various tissues. SDS-polyacrylamide gel electrophoresis showed that the soluble proteins with molecular weights corresponding to 160, 120, 108, 99 and 38 kDa were absent in the liver of the starved group. In the pectoral muscle the soluble proteins with molecular weights corresponding to 69, 41 and 34 kDa were missing. The activity of malic enzyme in the liver, heart and pectoral muscle of the starved group decreased markedly whereas that of acetylcholinesterase increased markedly in the pectoral muscle (P < 0.005). It is concluded that in prolonged starvation acetylcholinesterase synthesis may be induced in tissues being subjected to protein catabolism and that this enzyme may be involved as a protease in protein degradation.
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PMID:Effect of prolonged starvation on the activities of malic enzyme and acetylcholinesterase in tissues of Japanese quail. 758 1

Differential gene expression at the transcriptional level was examined as an initial step in the investigation of the P(i) starvation response of Brassica nigra suspension cells. Total RNA was extracted from 7-day old cells grown in media containing either no P(i), 1.25 mM or 10 mM Pi. In vitro translation was carried out using their respective poly(A)+ RNA isolates and the resultant polypeptides were separated on a high-resolution SDS-PAGE gel. Scanning densitometry identified four polypeptides (ca. 31.7, 32.3, 52.5 and 64.8 kDa) present only in the P(i)-starved samples. Screening by differential hybridization was performed on a cDNA library constructed from mRNA isolated from P(i)-starved cells. Probes prepared from mRNA from P(i)-deficient and P(i)-sufficient cells identified a number of clones representing mRNA species that were preferentially transcribed under P(i) deficiency. These phosphate starvation-responsive (psr) clones were placed into eleven groups as determined by cross-hybridization. Northern blots showed that the corresponding genes are inducible in both mild and severe P(i) starvation conditions. Preliminary sequencing identified one of the clones as being homologous to beta-glucosidases from several plant species. The possible role of beta-glucosidase during Pi starvation and the identities of the other psr genes are discussed.
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PMID:Isolation of cDNA clones of genes with altered expression levels in phosphate-starved Brassica nigra suspension cells. 764 Mar 58

A stable DNA/protein complex having an apparent molecular mass of approximately 150 kDa was purified from nitrate-limited cultures of the cyanobacterium Synechococcus sp. strain PCC 7942. Amino-terminal peptide sequencing indicated that the polypeptide was structurally similar to the Dps protein of Escherichia coli; Dps is also known as the product of the starvation- and stationary-phase-inducible gene, pexB. The 150-kDa complex dissociated into a 22-kDa protein monomer after boiling in 2% SDS. The 150-kDa complex preparation had approximately a 10% nucleic acid content and upon dissociation released DNA fragments that were sensitive to S1 nuclease digestion. Immunoblot data indicated that the complex accumulates during stationary phase and during nitrogen, sulfur, and phosphorus limitation. DNA-binding assays indicated that the protein nonspecifically binds both linear and supercoiled DNA. Circular dichroism spectroscopy revealed that the Synechococcus sp. Dps-like protein contains extensive regions of alpha-helical secondary structure. We propose that the 150-kDa complex represents a hexameric aggregate of the Dps-like protein complexed with single-stranded DNA and serves to bind a portion of the chromosomal DNA under nutrient-limited conditions.
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PMID:Purification and characterization of a Synechococcus sp. strain PCC 7942 polypeptide structurally similar to the stress-induced Dps/PexB protein of Escherichia coli. 779 1

The Escherichia coli DnaK homologue in Vibrio sp. strain S14 was shown to possess chaperone function for translocation during carbon starvation. This was demonstrated by using the method of co-immunoprecipitation. DnaK co-precipitated with the carbon starvation-specific periplasmic space protein Csp5 three hours after the onset of carbon starvation. Pulse-chasing of the protein with radiolabelled methionine followed by the addition of an excess of unlabelled methionine demonstrated that the Csp5 protein was translocated across the inner membrane. Only the cytoplasmic unprocessed precursor form of Csp5 co-precipitated with DnaK. The non-covalent binding between the two proteins was found to be ATP-dependent, as the addition of ATP released the interaction between DnaK and the precursor form of Csp5, as was shown on silver-stained SDS-polyacrylamide gels and by Western blot analysis. We suggest that DnaK maintains the carbon starvation-inducible protein Csp5 in a translocation-competent form in the cytoplasm.
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PMID:The DnaK homologue of the marine Vibrio sp. strain S14 binds to the unprocessed form of a carbon starvation-specific periplasmic protein. 791 11

Confluent monolayer cultures of the bovine kidney cell line NBL-1 were starved of amino acids in the presence of tracer concentrations of [35S]-methionine. Fluorographs of SDS-polyacrylamide gel separated membrane proteins revealed increased labelling of at least two proteins in starved cells relative to those in cells grown in complete medium. The patterns of Coomassie blue stained proteins from Concanavalin A-purified fractions of cells grown under fed and amino acid-starved conditions were similar but fluorography indicated the presence of one major labelled glycoprotein with a molecular weight of 62 kD in starved cells which was not present in fed cells. N-terminal amino acid analysis of the first 15 amino acids of the 62 kD protein and a protein of 60 kD found in control cells identified both proteins as calreticulin. N-terminal amino acid sequence analysis of a second amino acid starvation-up-regulated protein identified it as glucose-regulated protein GRP78. The amino acid sequences of calreticulin, GRP78 and two transport proteins known to be induced in amino acid starvation, have a common motif near the C-terminal end of the molecule. It is suggested that calreticulin is a member of a novel class of stress proteins induced by amino acid starvation.
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PMID:Calreticulin--a stress protein induced in the renal epithelial cell line NBL-1 by amino acid deprivation. 795 7


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