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)

Many studies have shown alterations in the number of nuclear triiodothyronine receptor (NT3R) under pathophysiologic situations. Most of these studies were performed on the rat liver and it is not known whether NT3R in different tissues exhibits an alteration similar to that in the liver. We compared the change of nuclear receptor capacity for T3 in the liver and kidney during starvation and after T3 injection. Fasting for 72 h decreased maximal binding capacity (Cmax) in the rat liver receptor to 67% of the control, while it did not significantly change Cmax in the kidney. These changes in Cmax were parallel to those of nuclear protein concentrations in both tissues. Daily sc injection of T3 (20 micrograms/100 g body weight) for 3 days also caused the different alteration of Cmax in the liver and kidney. After T3, hepatic NT3R increased to 182% of the control, but renal NT3R increased only to 136%. Association constants were the same in all groups. These results show that changes of NT3R capacity under some conditions vary in different tissues.
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PMID:Different alterations of nuclear triiodothyronine receptor capacity in liver and kidney induced by starvation and triiodothyronine administration. 298 41

Protein prenylation is a posttranslational modification involving the covalent attachment of a prenyl lipid to a cysteine at or near the COOH terminus of a protein. It is required for membrane localization and efficient function of a number of cytoplasmic as well as nuclear proteins including the proto-oncogenic and activated forms of Ras. Farnesylation in conjunction with a nuclear localization signal has been shown to be necessary to target newly synthesized nuclear lamins to the inner nuclear envelope membrane. It is, however, not clear where in the cell isoprenylation of nuclear lamins takes place. In this study we describe in vivo and in vitro experiments on the isoprenylation of the Xenopus oocyte nuclear lamin B3. We show by kinetic analysis that newly synthesized lamins are isoprenylated in the cytosol of oocytes before uptake into the nucleus. From our data it can be concluded that isoprenylation of lamins in the nucleus, as it is observed under certain conditions of isoprene starvation, represents a default pathway rather than the physiological situation. We further analyzed the capacity of isolated nuclei to carry out isoprenylation of B3. Our results are in line with a dual localization of a protein farnesyltransferase in the cytosol and nuclei of amphibian oocytes. Implications for the possible functions of a nuclear protein farnesyltransferase as well as possible mechanisms of the selective inhibition of farnesylation of cytoplasmic proteins by peptidomimetics are discussed.
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PMID:Analysis of nuclear lamin isoprenylation in Xenopus oocytes: isoprenylation of lamin B3 precedes its uptake into the nucleus. 769 83

Prothymosin alpha (ProT alpha) is a nuclear protein related to cell proliferation. Its gene is highly activated during postnatal development at stages containing many proliferating but also differentiating cells. In this report, a study on ProT alpha gene expression during differentiation of human myeloid leukemic (HL-60) cells was undertaken to analyze the possible association of ProT alpha to cell differentiation. When HL-60 cells were induced to differentiate to granulocytes (using retinoic acid) or monocyte/macrophages (using 12-O-tetradecanoylphorbol-13-acetate), a marked down-regulation in the levels of ProT alpha transcript was found. When cell division of immature HL-60 cells was interrupted by either treatment with hydroxyurea or serum starvation, ProT alpha gene expression was not significantly altered. These findings suggest that loss of ProT alpha mRNA in induced HL-60 cells is a differentiation-related event. Examination of the stability of ProT alpha mRNA showed that the stabilization of the ProT alpha transcript is differentially regulated in the two HL-60 lineages. Nuclear run-on experiments revealed that during HL-60 differentiation, the transcriptional activity of the ProT alpha gene does not experience significant variations.
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PMID:Differentiation-linked expression of prothymosin alpha gene in human myeloid leukemic cells. 841

1. We have established a murine hybridoma (F86) that secretes a monoclonal antibody (MoAb) specific for a 120 kDa nuclear protein (p120). p120 is expressed in all human cell lines investigated, whether of tumor or normal cell origin. 2. However, expression of p120 is significantly higher in neoplastic cells than in normal cells. The amount of p120 is relatively constant through the cell cycle and does not appear to be modulated by 72 hr serum starvation. 3. These results suggest that p120 plays some role in nuclear events associated with neoplastic phenotypes rather than in cell proliferation. 4. In situ immunofluorescence analyses indicate that p120 is located exclusively in nuclei of interphase cells. It is not present in nucleoli. 5. During mitosis, p120 is distributed in the cytoplasm and is not associated with condensed chromosomes which, together with RNAse experiments, suggests that it may be associated with hnRNA or hnRNP particles. 6. Western blot analyses indicate that p120 consists of two molecular weight forms which differ by 2-3 kDa in reduced SDS-PAGE, and several isoelectric variants in the acidic range. 7. Fractionation studies indicate that p120 has accessible free sulfhydryl group(s) and can bind ssDNA and heparin. 8. A partial cDNA clone, encoding the carboxyl terminus of p120, was isolated from a lambda gt11 library which had been prepared from human hepatoma cells (KYN-1). 9. Sequence analysis of the open reading frame revealed two possible nuclear localization sequences and several clusters of acidic amino acid residues, including a continuous run of 11 glutamic acid residues. 10. Northern blot analyses of human hepatoma RNA revealed hybridization to three transcripts which are about 4.1, 3.6, and 0.6 kb in size. 11. Dot blot analyses show that these transcripts are about 10-fold more abundant in KYN-1 hepatoma cells than in normal liver cells.
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PMID:A tumor-associated 120 kDa nuclear protein: characterization using a monoclonal antibody and a partial cDNA clone. 844 14

Biological responses to thyroid hormones are mediated by the nuclear thyroid hormone receptor (TR). Alterations in the maximal triiodothyronine (T3)-binding capacity (Cmax) of TR measured using a ligand binding assay have been reported under some pathophysiological conditions. Northern blot analysis has indicated that TR mRNA concentrations do not necessarily correlate with Cmax levels. For example, although the decrease in Cmax in rat liver induced by prolonged fasting is well established, TR mRNA concentrations have been reported to be constant. In the present study, we examined starvation-induced changes in TR by Western blot with anti-TR(alpha 1 + beta)antiserum and by Scatchard plot analysis. Starvation of rats for 72 hours decreased Cmax in the liver to 72.5% of control levels. The 47- and 55-kd TR proteins detected in hepatic nuclear extract by Western blotting also decreased to 64% and 66% of control values, respectively. The starvation-induced changes in Cmax and TR protein levels paralleled the change in total hepatic nuclear protein concentration. These results suggest that the decrease in T3-binding activity of the TR is due to a reduction of the TR protein itself.
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PMID:Starvation-induced decrease in the maximal binding capacity for triiodothyronine of the thyroid hormone receptor is due to a decrease in the receptor protein. 876 54

The high molecular weight (HMW) forms (24, 22.5, and 22 kDa) of basic fibroblast growth factor-2 (FGF-2) contain an N-terminal extension responsible for their predominantly nuclear localization. These forms of FGF-2 are post-translationally modified, resulting in a 1- to 2-kDa increase in apparent molecular mass. Here we show that this post-translational modification is inhibited by methionine starvation and by the methyltransferase inhibitors 5'-deoxy-5'-methylthioadenosine (MTA) and 3-deaza-adenosine. Inhibition of the methylation-dependent modification results in a significant decrease in HMW FGF-2 nuclear accumulation, suggesting that methylation is relevant to the intracellular distribution of these forms of FGF-2. Treatment with MTA does not affect either the synthesis or the intracellular fate of another nuclear protein, the SV40 large T antigen, demonstrating that this drug does not have a generalized effect on nuclear protein accumulation. These results link HMW FGF-2 post-translational modification to its intracellular distribution.
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PMID:Methylation of high molecular weight fibroblast growth factor-2 determines post-translational increases in molecular weight and affects its intracellular distribution. 885 68

Stress modifies all aspects of cellular physiology, including the targeting of macromolecules to the nucleus. To determine how distinct types of stress affect classical nuclear protein import, we followed the distribution of NLS-GFP, a reporter protein containing a classical nuclear localization sequence (NLS) fused to green fluorescent protein GFP. Nuclear accumulation of NLS-GFP requires import to be constitutively active; inhibition of import redistributes NLS-GFP throughout the nucleus and cytoplasm. In the yeast Saccharomyces cerevisiae, starvation, heat shock, ethanol and hydrogen peroxide rapidly inhibited classical nuclear import, whereas osmotic stress had no effect. To define the mechanisms underlying the inhibition of classical nuclear import, we located soluble components of the nuclear transport apparatus. Failure to accumulate NLS-GFP in the nucleus always correlated with a redistribution of the small GTPase Gsp1p. Whereas predominantly nuclear under normal conditions, Gsp1p equilibrated between nucleus and cytoplasm in cells exposed to starvation, heat, ethanol or hydrogen peroxide. Furthermore, analysis of yeast strains carrying mutations in different nuclear transport factors demonstrated a role for NTF2, PRP20 and MOG1 in establishing a Gsp1p gradient, as conditional lethal alleles of NTF2 and PRP20 or a deletion of MOG1 prevented Gsp1p nuclear accumulation. On the basis of these results, we now propose that certain types of stress release Gsp1p from its nuclear anchors, thereby promoting a collapse of the nucleocytoplasmic Gsp1p gradient and inhibiting classical nuclear protein import.
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PMID:Stress-mediated inhibition of the classical nuclear protein import pathway and nuclear accumulation of the small GTPase Gsp1p. 1102 3

Phosphate (Pi) deficiency is a major nutritional problem faced by plants in many agro-ecosystems. This deficiency results in altered gene expression leading to physiological and morphological changes in plants. Altered gene expression is presumed to be due to interaction of regulatory sequences (cis-elements) present in the promoters with DNA binding factors (trans-factors). In this study, we analyzed the expression and DNA-protein interaction of promoter regions of Pi starvation-induced genes AtPT2 and TPSI1. AtPT2 encodes the high-affinity Pi transporter in Arabidopsis, whereas TPSI1 codes for a novel gene induced in the Pi-starved tomato (Lycopersicon esculentum). Expression of AtPT2 was induced rapidly under Pi deficiency and increased with decreasing concentrations of Pi. Abiotic stresses except Pi starvation had no affect on the expression of TPSI1. DNA mobility-shift assays indicated that specific sequences of AtPT2 and TPSI1 promoter interact with nuclear protein factors. Two regions of AtPT2 and TPSI1 promoters specifically bound nuclear protein factors from Pi-sufficient plants. Interestingly, the DNA binding activity disappeared during Pi starvation, leading to the hypothesis that Pi starvation-induced genes may be under negative regulation.
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PMID:Negative regulation of phosphate starvation-induced genes. 1174 29

In fission yeast, nutrient starvation induces physiological, biochemical, and morphological changes that enable survival. Collectively these changes are referred to as stationary phase. We have used a green fluorescent protein random insertional mutagenesis system to isolate two novel stress-response proteins required in stationary phase. Ish1 is a nuclear envelope protein that is present throughout the cell cycle and whose expression is increased in response to stresses such as glucose and nitrogen starvation, as well as osmotic stress. Expression of Ish1 is regulated by the Spc1 MAPK pathway through the Atf1 transcription factor. Although overexpression of Ish1 is lethal, cells lacking ish1 exhibit reduced viability in stationary phase. Bis1 is a novel interacting partner of Ish1. Bis1 is the Schizosaccharomyces pombe member of the ES2 nuclear protein family found in Mus musculus, Drosophila melanogaster, Homo sapiens, and Arabidopsis thaliana. Overexpression of Bis1 results in a cell elongation phenotype, whereas bis1(-) cells exhibit a reduced viability in stationary phase similar to that seen in ish1(-) cells.
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PMID:The fission yeast ES2 homologue, Bis1, interacts with the Ish1 stress-responsive nuclear envelope protein. 1175 18

Abnormalities in regulation of the beta-amyloid precursor protein (APP) gene might be a crucial factor in Alzheimer's disease (AD). Our aim is to study the role of a specific proximal APP promoter element under the apoptotic condition. Our transfection studies with APP promoter deletion constructs indicate that each cell type differently regulates promoter activity. The minimum region that was sufficient to drive basal promoter activity in neuronal PC12 and neuroblastoma SK-N-SH cells was -75/+104 and -47/+104 bp, respectively. In SK-N-SH cells, the -47/+104 construct displayed the highest promoter activity, and the -75/-46 region acted as a negative regulatory element. Results from the gel electrophoretic mobility shift assay (EMSA) indicate that the -75/-46 region binds to a distinct DNA-protein complex with nuclear protein(s) from HeLa, PC12, NIH-3T3, and neuroblastoma cells. EMSA results from HeLa cells, which were stimulated by serum starvation (SR), indicate a significant induction in the signal of the DNA-protein complex from controls. EMSA results from PC12 cells, which were subjected to hypoxia, indicate a significant reduction in the signal. Our results suggest that the -75/-46 region binds to a protein that is upregulated in serum starvation, and downregulated in hypoxia. Because serum starvation contributes to the induction of apoptosis, these results suggest a role of the 30-bp proximal APP promoter element in enhanced apoptotic neuronal cell death.
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PMID:A proximal gene promoter region for the beta-amyloid precursor protein provides a link between development, apoptosis, and Alzheimer's disease. 1503 5


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