Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The signals controlling the abundance of transcripts up-regulated (pTIP27, pTIP31, and pTIP32) or down-regulated (pTIP20 and pTIP21) after harvest in asparagus (Asparagus officinalis L.) spears were examined. pTIP27 and pTIP31 are known to encode asparagine synthetase (AS) and a beta-galactosidase (beta-gal) homolog, respectively. The nucleotide sequences of pTIP20, pTIP21, and pTIP32 were determined, and they encode histone 3, histone 2B, and an unknown product, respectively. Changes in respiration, soluble sugars, and abundance of the five mRNAs were similar in the tips stored as 30-mm lengths or as part of 180-mm spears. We previously hypothesized that sugars may regulate the level of AS transcripts in asparagus tissue. Asparagus cell cultures were used to test the role of sugar status may regulate the level of AS transcripts in asparagus tissue. Asparagus cell cultures were used to test the role of sugar status in regulating gene expression. Transcript abundance for AS, beta-gal, and pTIP32 was low in cells in sugar-containing medium but increased within 12 h after transferring cells to a sugar-free medium. Histone 3 and histone 2B transcripts were, in general, abundant in cells on sugar-containing medium but declined in abundance when transferred to sugar-free medium. When cells were returned to sugar-containing medium the abundance of transcripts for histone 3 and histone 2B increased, whereas that for AS, beta-gal, and pTIP32 decreased. Soluble sugar levels are known to decline rapidly in the tips of harvested spears. Metabolic regulation by sugar status may have a major influence on gene expression in asparagus spears and other tissue after harvest.
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PMID:Sugar regulation of harvest-related genes in asparagus. 875 87

Real-time quantitative polymerase chain reaction (QPCR) using the Roche LightCycler was used to verify the expression of asparagine synthetase (ASNS) identified by microarray analysis as a target of p53 transrepression and mutant p53 transactivation. A p53-null cell line derived from lung carcinoma, H1299, was infected with recombinant adenovirus expressing wild-type (WT) p53, mutant p53-D281G, or beta-galactosidase as a control. After 24 h of infection, RNA was harvested and used for microarray analysis. ASNS was one of several genes whose expression was down-regulated by WT p53 and up-regulated in the presence of mutant p53. Expression levels of ASNS were measured relative to an exogenously applied quality-control nucleic acid template. Real-time PCR product accumulation was monitored using the intercalating dye, SYBR Green I, which exhibits a higher fluorescence upon binding of double-stranded DNA. Relative gene expression was calculated using conditions at the early stages of PCR, when amplification was logarithmic and, thus, could be correlated to initial copy number of gene transcripts. ASNS was found to be down-regulated in the presence of WT p53 and up-regulated by mutant p53.
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PMID:Real-time polymerase chain reaction quantitation of relative expression of genes modulated by p53 using SYBR Green I. 1282 26