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)

In this report we analyze the protein product of a growth arrest-specific gene, gas2, by means of an affinity-purified antibody raised against the protein produced in bacteria. The regulation of Gas2 biosynthesis reflects the pattern of mRNA expression (Schneider, C., R. King, and L. Philipson. 1988. Cell. 54:787-793): its relative level is tightly associated with growth arrest. Gas2 seems to be regulated also at the posttranslational level via a phosphorylation mechanism. Gas2 is well conserved during the evolution with the same apparent molecular mass (36 kD) between mouse and human. We also demonstrate that Gas2 is a component of the microfilament system. It colocalizes with actin fiber, at the cell border and also along the stress fiber, in growth-arrested NIH 3T3 cells. The pattern of distribution, detected in arrested cells, can also be observed in growing cells when they are microinjected with the purified GST-Gas2 protein. In none of the analyzed oncogene-transformed NIH 3T3 cell lines was Gas2 expression induced under serum starvation.
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PMID:Gas2, a growth arrest-specific protein, is a component of the microfilament network system. 160 87

The Drosophila glutathione S-transferase D genes encode a family of isozymes. We have determined the amino acid sequence of a new member of this family by nucleotide sequence analysis of a genomic DNA clone. The open reading frame of this intronless gene should encode an isozyme subunit of 211 amino acids. This sequence has significant homology to the E. coli stringent starvation protein, SSP, which is also a protein of two identical 211 amino acid subunits. The two proteins have very similar overall amino acid composition as well. It is possible that SSP may be a glutathione S-transferase(s) in E. coli or is evolutionarily related to glutathione S-transferases. Because SSP is known to be tightly associated with the RNA polymerase holoenzyme during purification, it is conceivable that Drosophila glutathione S-transferase(s) may potentially interact with the transcription machinery in a fashion similar to SSP's interaction with E. coli RNA polymerase holoenzyme.
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PMID:Drosophila glutathione S-transferases have sequence homology to the stringent starvation protein of Escherichia coli. 173 92

The activities of peroxisomal beta-oxidation, cytosolic and microsomal epoxide hydrolase as well as soluble glutathione S-transferases have been determined in the livers of alloxan- and streptozotocin-diabetic male Fischer-344 rats. Five, seven and ten days after initiation of diabetes serum glucose levels were elevated 3.6-, 5.7- to 6.2- and 6-fold, while the activities of peroxisomal beta-oxidation and cytosolic epoxide hydrolase were elevated 1.5- and 2.5-fold, 1.4- and 2.7-fold and 1.3- and 2.0-fold, respectively. The activities of microsomal epoxide hydrolase and glutathione S-transferases were reduced to about 71% and 80% of controls. Application of 10 I.U./kg depot insulin twice a day for 10 consecutive days to alloxan-diabetic individuals approximately restored the initial glucose levels and enzyme activities except for peroxisomal beta-oxidation. Starvation of Fischer-344 rats for 48 hours and 5 days similarly resulted in a 1.3-fold to 2.1-fold and 1.2- to 1.6-fold increase in peroxisomal beta-oxidation and cytosolic epoxide hydrolase activity, respectively. Microsomal epoxide hydrolase was significantly decreased to 57% and 61% of control activity whereas glutathione S-transferase was only marginally reduced to 91% and 92%. Except for glutathione S-transferases initial enzyme activities were restored upon refeeding within 10 days. These results are similar to those obtained upon feeding of hypolipidemic compounds with peroxisome proliferating activity, and may indicate that high levels of free fatty acids or their metabolites which are known to accumulate in liver in both metabolic states may act as endogenous peroxisome proliferators.
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PMID:Effect of diabetes and starvation on the activity of rat liver epoxide hydrolases, glutathione S-transferases and peroxisomal beta-oxidation. 268 56

Depletion of hepatic glutathione in male rats by starvation caused a significant increase in microsomal glutathione S-transferase activity, which was not affected by acute ethanol pretreatment. An additional depletion in fasted rats by diethylmaleate (0.5 g/kg) caused a further increase in the enzyme activity, but this increase was delayed in ethanol intoxicated rats. Although ethanol caused a small increase in hepatic microsomal lipid peroxidation in control animals, this effect of ethanol was not observed in diethylmaleate treated rats and thus was apparently not responsible for the delay in enzyme activation. It is suggested that the activation of microsomal glutathione S-transferase activity towards 1-chloro-2,4-dinitrobenzene in glutathione-depleted rat liver may be produced by changes in thiol/disulfid ratio and/or some reactive oxygen species.
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PMID:Effect of ethanol on the microsomal glutathione S-transferase activity in glutathione-depleted rat liver. 401 36

The PHO81 gene is thought to encode an inhibitor of the negative regulators (Pho80p and Pho85p) in the phosphatase (PHO) regulon. Transcription of PHO81 is regulated by Pi signals through the same PHO regulatory system. Elimination of the PHO81 promoter or its substitution by the GAL1 promoter revealed that stimulation of the PHO regulatory system requires both increased transcription of PHO81 and a Pi starvation signal. The predicted Pho81p protein contains 1,179 amino acids (aa) and has six repeats of an ankyrin-like sequence in its central region. The minimum amino acid sequence required for Pho81p function was narrowed down to a 141-aa segment (aa 584 to 724), which contains the fifth and sixth repeats of the ankyrin-like motif. The third to sixth repeats of the ankyrin-like motif of Pho81p have significant similarities to that of p16INK4, which inhibits activity of the human cyclin D-CDK4 kinase complex. Deletion analyses revealed that the N- and C-terminal regions of Pho81p behave as negative and positive regulatory domains, respectively, for the minimal 141-aa region. The negative regulatory activity of the N-terminal domain was antagonized by a C-terminal segment of Pho81p supplied in trans. All four known classes of PHO81c mutations that show repressible acid phosphatase activity in high-Pi medium affect the N-terminal half of Pho81p. An in vitro assay showed that a glutathione S-transferase-Pho81p fusion protein inhibits the Pho85p protein kinase. Association of Pho81p with Pho85p or with the Pho80p-Pho85p complex was demonstrated by the two-hybrid system.
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PMID:Functional domains of Pho81p, an inhibitor of Pho85p protein kinase, in the transduction pathway of Pi signals in Saccharomyces cerevisiae. 782 64

Bacteriophage P1 is unable to form plaques on E. coli hosts lacking a functional sspA gene. However, sspA mutants can be infected by P1, resulting in the synthesis of P1 early gene products and accumulation of P1 DNA, but without P1 late gene product formation or host lysis. Overexpression of the stringent starvation protein (SspA) as a glutathione-S-transferase fusion results in complementation of the sspA mutation and production of viable viral particles as in sspA+ strains. This suggests that the GST-SspA protein functions in vivo in a similar manner as native SspA with respect to P1 replication. Here, evidence is presented that shows that SspA binds to RNA-polymerase. This supports the notion that SspA is involved in P1 replication since it is known that P1 requires host RNA-polymerase activity to replicate and this suggests a mechanism by which P1 redirects E. coli RNA-polymerase specificity from P1 early to P1 late genes.
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PMID:Glutathione S-transferase-sspA fusion binds to E. coli RNA polymerase and complements delta sspA mutation allowing phage P1 replication. 819 64

BRCA1, a familial breast and ovarian cancer susceptibility gene encodes nuclear phosphoproteins that function as tumor suppressors in human breast cancer cells. Previously, we have shown that overexpression of a BRCA1 splice variant BRCA1a accelerates apoptosis in human breast cancer cells. In an attempt to determine whether the subcellular localization of BRCA1 is cell cycle regulated, we have studied the subcellular distribution of BRCA1 in asynchronous and growth arrested normal, breast and ovarian cancer cells using different BRCA1 antibodies by immunofluorescence and immunohistochemical staining. Upon serum starvation of NIH3T3, some breast and ovarian cancer cells, most of the BRCA1 protein redistributed to the nucleus revealing a new type of regulation that may modulate the activity of BRCA1 gene. We have also characterized two new variant BRCA1 proteins (BRCA1a/p110 and BRCA1b/ p100) which are phosphoproteins containing phosphotyrosine. Immunofluorescence and Western blotting analysis indicate cytoplasmic and nuclear localization of BRCA1a and BRCA1b proteins. To elucidate the biological function of BRCA1, we created a bacterial fusion protein of glutathione-transferase (GST) and BRCA1 zinc finger domain and detected two cellular proteins with molecular weights of approximately 32 and 65 kD, one of which contains phosphotyrosine designated p32 and p65 BRCA1 interacting proteins (BIP) that specifically interact with BRCA1. Western blot analysis of BIP with cyclins/CDKs and E2F antisera indicated association with cdc2, cdk2, cdk4, cyclin B, cyclin D, cyclin A and E2F-4 but not with cdk3, cdk5, cdk6, E2F-1, E2F-2, E2F-3, E2F-5 and cyclin E. Furthermore, we have also demonstrated a direct interaction of in vitro translated BRCA1a and BRCA1b proteins with recombinant cyclin A, cyclin B1, cyclin D1, cdc2, cdk2 and E2F fusion proteins in vitro. Taken together these results seem to suggest that BRCA1 could be an important negative regulator of cell cycle that functions through interaction with E2F transcriptional factors and phosphorylation by cyclins/cdk complexes with the zinc ring finger functioning as a major protein-protein interaction domain. If the interactions we observe in vitro is also seen in vivo then it may be possible that lack or impaired binding of the disrupted BRCA1 proteins to E2F, cyclins/CDKs in patients with mutations in the zinc finger domain could deprive the cell of an important mechanism for braking cell proliferation leading to the development of breast and ovarian cancers.
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PMID:BRCA1 proteins are transported to the nucleus in the absence of serum and splice variants BRCA1a, BRCA1b are tyrosine phosphoproteins that associate with E2F, cyclins and cyclin dependent kinases. 924 50

A new panel of anti-A-type lamin monoclonal antibodies was generated. Epitope mapping was performed by immunoblotting against GST-lamin fusion peptides. Epitopes were mapped to four different regions of human lamin A and three different regions of human lamin C. The distribution of A-type lamins was compared with the distribution of the proliferation marker Ki67 in proliferating and quiescent cultures of human dermal fibroblasts (HDFs) using a double indirect immunofluorescence assay. Antibodies that had been mapped to a region of the lamin C tail stained the nuclear envelope of proliferating and quiescent cells equally brightly. In contrast, antibodies recognizing epitopes in the head domain and rod domain of lamins A and C and the tail domain of lamin A stained the nuclear envelope of quiescent cells strongly but reacted poorly or not at all with the nuclear envelope of proliferating cells. Changes in the level of expression of lamins A and C were not detected in immunoblotting assays. However, epitope masking was revealed, and this occurred by two distinct mechanisms. Epitope masking in the head domain of lamins A and C occurred as a result of protein phosphorylation. Epitope masking in the rod domain of lamins A and C and in the tail domain of lamin A occurred through a physical association between the lamin and chromatin and/or other nuclear proteins. The cell cycle timing of epitope masking was investigated in HDFs that had been restimulated after serum starvation. Extensive epitope masking in restimulated cells only occurred after cells had passed through mitosis. These results are consistent with the hypothesis that rearrangement of A-type lamin filaments, as cells progress from a quiescent to a proliferating state, results in altered lamina associations.
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PMID:Cell cycle changes in A-type lamin associations detected in human dermal fibroblasts using monoclonal antibodies. 936 40

The yeast ENA1/PMR2A gene encodes a cation extrusion ATPase in Saccharomyces cerevisiae which is essential for survival under salt stress conditions. One important mechanism of ENA1 transcriptional regulation is based on repression under normal growth conditions, which is relieved by either osmotic induction or glucose starvation. Analysis of the ENA1 promoter revealed a Mig1p-binding motif (-533 to -544) which was characterized as an upstream repressing sequence (URSMIG-ENA1) regulated by carbon source. Its function was abolished in a mig1 mig2 double-deletion strain as well as in either ssn6 or tup1 single mutants. A second URS at -502 to -513 is responsible for transcriptional repression regulated by osmotic stress and is similar to mammalian cyclic AMP response elements (CREs) that are recognized by CREB proteins. This URSCRE-ENA1 element requires for its repression function the yeast CREB homolog Sko1p (Acr1p) as well as the integrity of the Ssn6p-Tup1p corepressor complex. When targeted to the GAL1 promoter by fusing with the Gal4p DNA-binding domain, Sko1p acts as an Ssn6/Tup1p-dependent repressor regulated by osmotic stress. A glutathione S-transferase-Sko1 fusion protein binds specifically to the URSCRE-ENA1 element. Furthermore, a hog1 mitogen-activated protein kinase deletion strain could not counteract repression on URSCRE-ENA1 during osmotic shock. The loss of SKO1 completely restored ENA1 expression in a hog1 mutant and partially suppressed the osmotic stress sensitivity, qualifying Sko1p as a downstream effector of the HOG pathway. Our results indicate that different signalling pathways (HOG osmotic pathway and glucose repression pathway) use distinct promoter elements of ENA1 (URSCRE-ENA1 and URSMIG-ENA1) via specific transcriptional repressors (Sko1p and Mig1/2p) and via the general Ssn6p-Tup1p complex. The physiological importance of the relief from repression during salt stress was also demonstrated by the increased tolerance of sko1 or ssn6 mutants to Na+ or Li+ stress.
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PMID:Repressors and upstream repressing sequences of the stress-regulated ENA1 gene in Saccharomyces cerevisiae: bZIP protein Sko1p confers HOG-dependent osmotic regulation. 985 77

Considerable evidence suggests that oxidative stress plays an important role in tissue damage associated with hypoglycemia and other metabolic disorders. The altered brain neurotransmitters metabolism, cerebral electrolyte contents, and impaired blood-brain barrier function may contribute to CNS dysfunction in hypoglycemia. The present study elucidates the effect of starvation and insulin-induced hypoglycemia on the free radical scavanger system--reduced glutathione (GSH) content, glutathione S-transferase (GST), glutathione peroxidase (GPx), glutathione reductase (GR), gamma-glutamyl transpeptidase (gamma-GTP), gamma-glutamyl cystein synthetase (gamma-GCS), catalase and superoxide dismutase (SOD), and mitochondrial electron transport chain (ETC) complexes I-IV from three different regions of rat brain, namely cerebral hemispheres (CH), cerebellum (CB), and brainstem (BS). Peripheral organs, such as liver and kidney, were also studied. Significant changes in these enzymic activities were observed. The analysis of such alterations is important in ultimately determining the basis of neuronal dysfunction during metabolic stress conditions, such as hypoglycemia, and also defining the nature of these changes may help to develop therapeutic means to cure metabolically stressed tissues.
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PMID:Effect of starvation and insulin-induced hypoglycemia on oxidative stress scavenger system and electron transport chain complexes from rat brain, liver, and kidney. 1032 15


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