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)

A promoterless radial spoke protein RSP3 gene has been used to identify promoter regions in the genome of Chlamydomonas reinhardtii. The acceptor strain pf-14 arg7 was transformed with a linearized vector containing the ARG 7.8 gene as a selection marker and a promoterless RSP3 gene. The frequency at which the motility was restored in transformants varied from 2-3%. Several of these were motile only in ammonium-free medium, indicating that the procedure could be used to select inducible promoters. Transformation of nitrogen-starved cells produced about twice as many transformants which were only motile in ammonium-free medium. Since one of the tagging vectors contained an RSP3 gene with a hybridization flag in its 3' untranslated region, it was possible to estimate the size of the new RSP3 transcripts in transformants. The results suggested that in most cases a hybrid RNA was generated consisting of the tagged gene transcript and reporter gene RNA. By 5' RACE, these parts of the new transcripts were amplified and it was shown that the generated DNA fragments could be used to clone a tagged gene. One such example, gene 2BC9, is predicted to code for a mitochondrial matrix protein. The tagging procedure will be optimized for cloning genes induced by nitrogen starvation, the cue for gametogenesis.
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PMID:A promoter trap for Chlamydomonas reinhardtii: development of a gene cloning method using 5' RACE-based probes. 922 72

In order to identify gene products associated with the development of acquired therapeutic resistance by prostate cancer cells, we created two novel apoptosis-resistant prostate cancer cell lines, LNCaP-TR (phorbol-ester [TPA]-Resistant) and LNCaP-SSR (Serum Starvation-Resistant) by repeated transient exposure of cultured human LNCaP cells to apoptotic stimuli followed by expansion of surviving cell populations. These cell lines were found to be cross-resistant to the alternative selective agent and also hormone-resistant when xenografted into castrated male immunodeficient mice. RNA from the LNCaP-TR line was comparatively screened using a subtractive hybridization-PCR procedure. This allowed us to identify a 249 bp cDNA fragment that hybridized to a 4.8 kb mRNA preferentially expressed by the apoptosis-resistant cells. Using RACE procedures, we cloned and sequenced the complete 4.8 kb cDNA. It is an unusual member of the protocadherin gene family containing two large overlapping open reading frames encoding homologous polypeptides, one having a signal sequence and the other lacking a signal sequence and we refer to it as protocadherin-PC. LNCaP cells directly transformed with protocadherin-PC cDNA were comparatively resistant to phorbol-ester induced apoptosis. Antibody recognition studies demonstrating the cytoplasmic nature of the protcadherin-PC translation product and its propensity to bind beta-catenin suggest that it might influence the apoptotic sensitivity of prostate cancer cells through a unique mechanism.
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PMID:The emergence of protocadherin-PC expression during the acquisition of apoptosis-resistance by prostate cancer cells. 1242 Feb 23

A putative glucose transporter, GLUT1, is reported for Atlantic cod Gadus morhua. A combination of RT-PCR, RLM-RACE and genome walking were used to articulate a 4560 bp cDNA (GenBank accession number AY526497). It contains a 149 bp 5' UTR, a 1470 bp open reading frame and a 2941 bp 3' UTR. At the nucleotide level, the cod GLUT1 ORF shares 78.2% sequence identity to human GLUT1 and the deduced amino acid sequence clusters with GLUT1s from rainbow trout and carp. GLUT1 transcript is highly expressed in brain, gill, heart and kidney and expressed to a lower level in at least six other tissues. Expression is evident immediately upon fertilization of eggs. Six hours of hypoxia at 40% DO(2) did not alter expression levels in brain, gill, heart or kidney. The level of expression is not substantially altered in heart during low temperature challenge, although there is a suggestion that colder temperature could lead to lower levels of expression, consistent with the concept that the cold-acclimated heart has a reduced dependence upon glucose as a metabolic fuel. Two months of starvation did not significantly alter the level of expression of GLUT1 in heart. This is in marked contrast to the rat heart where fasting leads to a substantial decrease in GLUT1 levels. Overall, there is a ubiquitous tissue distribution of GLUT1, consistent with other species, and the level of gene expression, especially in heart, is relatively constant over a range of physiological conditions.
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PMID:Sequence and expression of a constitutive, facilitated glucose transporter (GLUT1) in Atlantic cod Gadus morhua. 1557 63

In invertebrates, neuropeptide F (NPF) peptides share structural similarity with vertebrate neuropeptide Y, which regulates food consumption, circadian rhythms, anxiety, and other physiological processes. The insect neuropeptide F receptors belong to the G protein-coupled receptor (GPCR) rhodopsin family. We have cloned the fire ant putative short NPF receptor using PCR and RACE methods. The complete 2,185-bp cDNA encodes a 387-residue protein with a predicted GPCR seven transmembrane region structure. We propose that the sequence of the honey bee short NPF receptor, which has not yet been annotated, encodes a protein of 393 residues. In fire ant mated queens, receptor transcripts were detected in the brain, midgut, hindgut, Malpighian tubules, fat body, and ovaries. The highest transcriptional expression was found in the brain. The downregulation of the fire ant short NPF receptor transcriptional expression in the brain with starvation suggests that the short NPF signal transduction cascade may play a role in feeding regulation in fire ant mated queens.
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PMID:The short neuropeptide F-like receptor from the red imported fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae). 1655 71

The evolution of anisogamy/oogamy in the colonial Volvocales might have occurred in an ancestral isogamous colonial organism like Gonium pectorale. The unicellular, close relative Chlamydomonas reinhardtii has a mating-type (MT) locus harboring several mating-type-specific genes, including one involved in mating-type determination and another involved in the function of the tubular mating structure in only one of the two isogametes. In this study, as the first step in identifying the G. pectorale MT locus, we isolated from G. pectorale the ortholog of the C. reinhardtii mating-type-determining minus-dominance (CrMID) gene, which is localized only in the MT- locus. 3'- and 5'-RACE RT-PCR using degenerate primers identified a CrMID-orthologous 164-amino-acid coding gene (GpMID) containing a leucine-zipper RWP-RK domain near the C-terminal, as is the case with CrMID. Genomic Southern blot analysis showed that GpMID was coded only in the minus strain of G. pectorale. RT-PCR revealed that GpMID expression increased during nitrogen starvation. Analysis of F1 progeny suggested that GpMID and isopropylmalate dehydratase LEU1S are tightly linked, suggesting that they are harbored in a chromosomal region under recombinational suppression that is comparable to the C. reinhardtii MT locus. However, two other genes present in the C. reinhardtii MT locus are not linked to the G. pectorale LEU1S/MID, suggesting that the gene content of the volvocalean MT loci is not static over time. Inheritance of chloroplast and mitochondria genomes in G. pectorale is uniparental from the plus and minus parents, respectively, as is also the case in C. reinhardtii.
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PMID:Identification of the minus-dominance gene ortholog in the mating-type locus of Gonium pectorale. 1820 74

Exopolysaccharide and several extracellular enzymes of Xanthomonas campestris pv. campestris (Xcc), the causative agent of black rot in crucifers, are virulence factors. In this study, sequence and mutational analysis has demonstrated that Xcc pehA encodes the major polygalacturonase, a member of family 28 of the glycosyl hydrolases. Using the 5' RACE (rapid amplification of cDNA ends) method, the pehA transcription initiation site was mapped at 102 nt downstream of a Clp (cAMP receptor protein-like protein)-binding site. Transcriptional fusion assays showed that pehA transcription is greatly induced by polygalacturonic acid, positively regulated by Clp and RpfF (an enoyl-CoA hydratase homologue which is required for the synthesis of cis-11-methyl-2-dodecenoic acid, a low-molecular-mass diffusible signal factor), subjected to catabolite repression, which is independent of Clp or RpfF, and repressed under conditions of oxygen limitation or nitrogen starvation. Our findings extend previous work on Clp and RpfF regulation to show that they both influence the expression of pehA in Xcc.
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PMID:Regulation of the pehA gene encoding the major polygalacturonase of Xanthomonas campestris by Clp and RpfF. 1831 17

Increased alanine aminotransferase (ALT) activity is associated with insulin resistance and the development of type 2 diabetes. The aim of this study was to characterize the modulation of cytosolic ALT expression in liver of gilthead sea bream (Sparus aurata) under conditions associated with increased gluconeogenesis and in streptozotocin (STZ)-treated fish. RT- and RACE-PCR assays allowed us to isolate a novel ALT isozyme (cALT2) generated from alternative splicing of cALT gene in S. aurata. HEK293 cells transfected with constructs expressing cALT2 as a C-terminal fusion with the enhanced green fluorescent protein allowed us to demonstrate that cALT2 is cytosolic. To unravel the molecular functions of cALT1 and cALT2 in liver of S. aurata, we examined tissue distribution, kinetic characterization of piscine cALT isozymes expressed in Saccharomyces cerevisiae, and regulation of hepatic cALT1 and cALT2 expression in various metabolic conditions. Kinetic analysis indicates that cALT2 is more efficient in catalysing the conversion of l-alanine to pyruvate than cALT1. Starvation increased cALT2 expression and decreased cALT1 mRNA in liver. Opposite effects were found in regularly fed fish at postprandial time 4-8h, and 6h after treatment with glucose or insulin. From these results we conclude that increased cALT2 expression occurred in liver under gluconeogenic conditions, while cALT1 was predominant during postprandial utilization of dietary nutrients. Since up-regulation of hepatic cALT2 expression occurred in STZ-induced diabetic S. aurata, increased hepatic cALT2 expression may be a promising marker in the prognosis of diabetes.
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PMID:A novel alternatively spliced transcript of cytosolic alanine aminotransferase gene associated with enhanced gluconeogenesis in liver of Sparus aurata. 1858 94

Prochlorococcus, an extremely small cyanobacterium that is very abundant in the world's oceans, has a very streamlined genome. On average, these cells have about 2,000 genes and very few regulatory proteins. The limited capability of regulation is thought to be a result of selection imposed by a relatively stable environment in combination with a very small genome. Furthermore, only ten non-coding RNAs (ncRNAs), which play crucial regulatory roles in all forms of life, have been described in Prochlorococcus. Most strains also lack the RNA chaperone Hfq, raising the question of how important this mode of regulation is for these cells. To explore this question, we examined the transcription of intergenic regions of Prochlorococcus MED4 cells subjected to a number of different stress conditions: changes in light qualities and quantities, phage infection, or phosphorus starvation. Analysis of Affymetrix microarray expression data from intergenic regions revealed 276 novel transcriptional units. Among these were 12 new ncRNAs, 24 antisense RNAs (asRNAs), as well as 113 short mRNAs. Two additional ncRNAs were identified by homology, and all 14 new ncRNAs were independently verified by Northern hybridization and 5'RACE. Unlike its reduced suite of regulatory proteins, the number of ncRNAs relative to genome size in Prochlorococcus is comparable to that found in other bacteria, suggesting that RNA regulators likely play a major role in regulation in this group. Moreover, the ncRNAs are concentrated in previously identified genomic islands, which carry genes of significance to the ecology of this organism, many of which are not of cyanobacterial origin. Expression profiles of some of these ncRNAs suggest involvement in light stress adaptation and/or the response to phage infection consistent with their location in the hypervariable genomic islands.
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PMID:The challenge of regulation in a minimal photoautotroph: non-coding RNAs in Prochlorococcus. 1876 76

Perennial ryegrass (Lolium perenne L.) is the most important turf and forage grass species of the temperate regions. It requires substantial input of nitrogen fertilizer for optimum yield. Improved nitrogen use efficiency (NUE) is therefore one of the main breeding targets. However, limited knowledge is currently available on the genes controlling NUE in perennial ryegrass. The aim of the present study was to isolate genes involved in ammonium transport and assimilation. In silico screening of a Lolium EST-library using known sequences of tonoplast intrinsic proteins (TIPs) and cytosolic glutamine synthetase (GS1) revealed a number of homologous sequences. Using these sequences, primers were designed to obtain the full-length sequences by RACE-PCR. Three TIP genes (LpTIP1;1, LpTIP1;2 and LpTIP2;1) and two GS genes (LpGS1a and LpGS1b) were isolated. Characterization in S. cerevisiae confirmed a function in ammonium transport for LpTIP1;1 and LpTIP2;1 and in synthesis of glutamine for LpGS1a and LpGS1b. Cytoimmunochemical studies showed that GS protein was present in the chloroplasts and cytosol of leaf cells, while TIP1 proteins localized to the tonoplast. At the expression level, Lolium GS1 genes responded to N starvation and re-supply in a manner consistent with functions in primary N assimilation and N remobilization. Similarly, the expression of LpTIPs complied with a role in vacuolar ammonium storage. Together, the reported results provide new understanding of the genetic basis for N assimilation and storage in ryegrass.
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PMID:Cloning, characterization and expression analysis of tonoplast intrinsic proteins and glutamine synthetase in ryegrass (Lolium perenne L.). 1965 46

A bHLH (basic helix-loop-helix domain) transcription factor involved in tolerance to Pi starvation was cloned from Zea mays with an RT-PCR coupled RACE approach and named ZmPTF1. ZmPTF1 encoded a putative protein of 481 amino acids that had identity with OsPTF1 in basic region. Real-time RT-PCR revealed that ZmPTF1 was quickly and significantly up-regulated in the root under phosphate starvation conditions. Overexpression of ZmPTF1 in maize improved root development, enhanced biomass both in hydroponic cultures and sand pots, and the plants developed more tassel branches and larger kernels when they were grown in low phosphate soil. Compared with wild type, overexpressing ZmPTF1 altered the concentrations of soluble sugars in transgenic plants, in which soluble sugars levels were lower in the leaves and higher in the roots. Overexpression of ZmPTF1 enhanced the expression of fructose-1,6-bisphosphatase and sucrose phosphate synthase1 participated in sucrose synthesis in the leaves but decreased them in the root, and reduced the expression of genes involved in sucrose catabolism in the roots. The modifications on the physiology and root morphology of the plants enhanced low phosphate tolerance and increased the yield under low phosphate conditions. This research provides a useful gene for transgenic breeding of maize that is tolerant to phosphate deficiency and is helpful for exploring the relationship between sugar signaling and phosphate concentrations in cells.
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PMID:Overexpression of transcription factor ZmPTF1 improves low phosphate tolerance of maize by regulating carbon metabolism and root growth. 2131 41


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