Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0848237 (acute stress)
 4,619 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Leaf, bark, xylem and root tissues were used to make nine cDNA libraries from non-stressed (control) 'Royal Gala' apple trees, and from 'Royal Gala' trees exposed to either low temperature (5 degrees C for 24 h) or water deficit (45% of saturated pot mass for 2 weeks). Over 22 600 clones from the nine libraries were subjected to 5' single-pass sequencing, clustered and annotated using blastx. The number of clusters in the libraries ranged from 170 to 1430. Regarding annotation of the sequences, blastx analysis indicated that within the libraries 65-72% of the clones had a high similarity to known function genes, 6-15% had no functional assignment and 15-26% were completely novel. The expressed sequence tags were combined into three classes (control, low-temperature and water deficit) and the annotated genes in each class were placed into 1 of 10 different functional categories. The percentage of genes falling into each category was then calculated. This analysis indicated a distinct downregulation of genes involved in general metabolism and photosynthesis, while a significant increase in defense/stress-related genes, protein metabolism and energy was observed. In particular, there was a three-fold increase in the number of stress genes observed in the water deficit libraries indicating a major shift in gene expression in response to a chronic stress. The number of stress genes in response to low temperature, although elevated, was much less than the water deficit libraries perhaps reflecting the shorter (24 h) exposure to stress. Genes with greater than five clones in any specific library were identified and, based on the number of clones obtained, the fold increase or decrease in expression in the libraries was calculated and verified by semiquantitative polymerase chain reaction. Genes, of particular note, that code for the following proteins were overexpressed in the low-temperature libraries: dehydrin and metallothionein-like proteins, ubiquitin proteins, a dormancy-associated protein, a plasma membrane intrinsic protein and an RNA-binding protein. Genes that were upregulated in the water deficit libraries fell mainly into the functional categories of stress (heat shock proteins, dehydrins) and photosynthesis. With few exceptions, the overall differences in downregulated genes were nominal compared with differences in upregulated genes. The results of this apple study are similar to other global studies of plant response to stress but offer a more detailed analysis of specific tissue response (bark vs xylem vs leaf vs root) and a comparison between an acute stress (24-h exposure to low temperature) and a chronic stress (2 weeks of water deficit).
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PMID:Expressed sequence tag analysis of the response of apple (Malus x domestica'Royal Gala') to low temperature and water deficit. 1829 16

Cancer cell metabolism differs from normal cells, yet the regulatory mechanisms responsible for these differences are incompletely understood, particularly in response to acute changes in the tumor microenvironment. HuR, an RNA-binding protein, acts under acute stress to regulate core signaling pathways in cancer through post-transcriptional regulation of mRNA targets. We demonstrate that HuR regulates the metabolic phenotype in pancreatic cancer cells and is critical for survival under acute glucose deprivation. Using three pancreatic cancer cell line models, HuR-proficient cells demonstrated superior survival under glucose deprivation when compared with isogenic cells with siRNA-silencing of HuR expression (HuR-deficient cells). We found that HuR-proficient cells utilized less glucose, but produced greater lactate, as compared with HuR-deficient cells. Acute glucose deprivation was found to act as a potent stimulus for HuR translocation from the nucleus to the cytoplasm, where HuR stabilizes its mRNA targets. We performed a gene expression array on ribonucleoprotein-immunoprecipitated mRNAs bound to HuR and identified 11 novel HuR target transcripts that encode enzymes central to glucose metabolism. Three (GPI, PRPS2 and IDH1) were selected for validation studies, and confirmed as bona fide HuR targets. These findings establish HuR as a critical regulator of pancreatic cancer cell metabolism and survival under acute glucose deprivation. Further explorations into HuR's role in cancer cell metabolism should uncover novel therapeutic targets that are critical for cancer cell survival in a metabolically compromised tumor microenvironment.
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PMID:HuR is a post-transcriptional regulator of core metabolic enzymes in pancreatic cancer. 2380 17

RNA-binding proteins (RBPs) play a major role during control of mRNA localization, stability, and translation and are central to most cellular processes. In the fission yeast Schizosaccharomyces pombe, the multiple K homology (KH) domain RBP Rnc1 downregulates the activity of the cell integrity pathway (CIP) via stabilization of pmp1 + mRNA, which encodes the Pmp1 phosphatase that inactivates Pmk1, the mitogen-activated protein kinase (MAPK) component of this signaling cascade. However, Rnc1 likely regulates the half-life/stability of additional mRNAs. We show that Rnc1 downregulates the activity of Sty1, the MAPK of the stress-activated MAPK pathway (SAPK), during control of cell length at division and recovery in response to acute stress. Importantly, this control strictly depends on Rnc1's ability to bind mRNAs encoding activators (Wak1 MAPKKK, Wis1 MAPKK) and downregulators (Atf1 transcription factor, Pyp1 and Pyp2 phosphatases) of Sty1 phosphorylation through its KH domains. Moreover, Sty1 is responsible for Rnc1 phosphorylation in vivo at multiple phosphosites during growth and stress, and these modifications trigger Rnc1 for proper binding and destabilization of the above mRNA targets. Phosphorylation by Sty1 prompts Rnc1-dependent mRNA destabilization to negatively control SAPK signaling, thus revealing an additional feedback mechanism that allows precise tuning of MAPK activity during unperturbed cell growth and stress.IMPORTANCE Control of mRNA localization, stability, turnover, and translation by RNA-binding proteins (RBPs) influences essential processes in all eukaryotes, including signaling by mitogen-activated protein kinase (MAPK) pathways. We describe that in the fission yeast Schizosaccharomyces pombe the RBP Rnc1 negatively regulates cell length at division during unperturbed growth and recovery after acute stress by reducing the activity of the MAPK Sty1, which regulates cell growth and differentiation during environmental cues. This mechanism relies on Rnc1 binding to specific mRNAs encoding both enhancers and negative regulators of Sty1 activity. Remarkably, multiple phosphorylation of Rnc1 by Sty1 favors RBP binding and destabilization of the above mRNAs. Thus, posttranscriptional modulation of MAP kinase signaling by RNA-binding proteins emerges as a major regulatory mechanism that dictates the growth cycle and cellular adaptation in response to the changing environment in eukaryotic organisms.
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PMID:RNA-Binding Protein Rnc1 Regulates Cell Length at Division and Acute Stress Response in Fission Yeast through Negative Feedback Modulation of the Stress-Activated Mitogen-Activated Protein Kinase Pathway. 3191 90