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 genomic clones of Sat gene encoding serine acetyltransferase (SATase), a key enzyme in cysteine biosynthesis in plants, were isolated from the genomic library of Citrullus vulgaris (watermelon). The determination of nucleotide sequence of 5.7 kilobase pair (kbp) length revealed the presence of two introns of 1939 basepair (bp) and 515 bp length in the gene. The transcription start point was determined by primer extension experiments. Southern blot analysis indicated the presence of a single copy of the Sat gene and a couple of additional related sequences in the genome of C. vulgaris. The expression of Sat was analyzed in watermelon plants growth under sulfur- and/or nitrogen-starved conditions and in the presence of pyrazole, O-acetylserine and N-acetylserine. Only slight increment (ca. 1.5-2-fold) of Sat gene expression was observed upon sulfur starvation for 48 h. Interestingly, the addition of pyrazole, which is a precursor of beta-pyrazolealanine (beta-PA) synthesized by SATase and cysteine/beta-PA synthase, enhanced the expression of Sat by ca. 2-fold.
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PMID:Genomic structure and expression analyses of serine acetyltransferase gene in Citrullus vulgaris (watermelon). 916 12

cDNAs encoding a high-affinity sulfate transporter and an adenosine 5'-phosphosulfate reductase from potato (Solanum tuberosum L. cv Desiree) have been cloned and used to examine the hypothesis that sulfate uptake and assimilation is transcriptionally regulated and that this is mediated via intracellular O-acetylserine (OAS) pools. Gas chromotography coupled to mass spectrometry was used to quantify OAS and its derivative, N-acetylserine. Treatment with external OAS increased sulfate transporter and adenosine 5'-phosphosulfate reductase gene expression consistent with a model of transcriptional induction by OAS. To investigate this further, the Escherichia coli gene cysE (serine acetyltransferase EC 2.3.1.30), which synthesizes OAS, has been expressed in potato to modify internal metabolite pools. Transgenic lines, with increased cysteine and glutathione pools, particularly in the leaves, had increased sulfate transporter expression in the roots. However, the small increases in the OAS pools were not supportive of the hypothesis that this molecule is the signal of sulfur (S) nutritional status. In addition, although during S starvation the content of S-containing compounds decreased (consistent with derepression as a mechanism of regulation), OAS pools increased only following extended starvation, probably as a consequence of the S starvation. Taken together, expression of these genes may be induced by a demand-driven model, via a signal from the shoots, which is not OAS. Rather, the signal may be the depletion of intermediates of the sulfate assimilation pathway, such as sulfide, in the roots. Finally, sulfate transporter activity did not increase in parallel with transcript and protein abundance, indicating additional posttranslational regulatory mechanisms.
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PMID:O-acetylserine and the regulation of expression of genes encoding components for sulfate uptake and assimilation in potato. 1580 76