Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The adjacent sacX and sacY genes are involved in sucrose induction of the Bacillus subtilis sacB gene by an antitermination mechanism. sacB, encoding the exoenzyme levansucrase, is also subject to regulation by the DegS-DegU signalling system. Using sacXY'-lacZ and sacX'-lacZ fusions, we show that the transcription of the sacX and sacY genes is both inducible by sucrose and regulated by DegU. sacX and sacY appear to constitute an operon, since the deletion of the sacX leader region abolished the expression of a sacXY'-lacZ fusion. The degU-dependent promoter was located by deletion analysis and reverse transcriptase mapping 300 nucleotides upstream from the sacX initiator codon. Sucrose induction of the sacX'-lacZ fusion requires either SacY or the homologous SacT antiterminator, which is involved in sucrose induction of the intracellular sucrase gene (sacPA operon). Sequence analysis of the sacX leader region revealed (20 nucleotides downstream from the transcription start site) a putative binding site for these regulators; however, no structure resembling a rho-independent terminator could be found overlapping this site, unlike the situation for sacPA and sacB. Deletion of a segment of the leader region located 100 nucleotides downstream from this site led to constitutive expression of the sacXY'-lacZ and sacX'-lacZ fusions. These results suggest that the mechanism of sucrose induction of sacXY is different from that of sacPA and sacB.
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PMID:Transcription of the Bacillus subtilis sacX and sacY genes, encoding regulators of sucrose metabolism, is both inducible by sucrose and controlled by the DegS-DegU signalling system. 140 Jan 59

Adenocarcinoma of the colon is one of the most prevalent and lethal of all human malignancies. The early diagnosis and management of this disease could be improved if biological markers, whose expression was restricted to malignant colon cells, were identified. Sucrase-isomaltase is a glycoprotein hydrolase expressed throughout the small intestine and fetal colon but not in the normal adult colon. This study shows that the expression of enzymatically active sucrase-isomaltase is a ubiquitous property of primary and metastatic colon adenocarcinoma. Significant sucrase enzyme activity (i.e., greater than 5 mU/mg protein) was observed in 16 colon carcinomas but not in adjacent normal colon mucosa. Sucrase-isomaltase messenger RNA was identified in all tumors using reverse transcriptase polymerase chain reaction. Using a quantitative polymerase chain reaction analysis, this study shows that the amount of sucrase-isomaltase messenger RNA in tumors examined (3.4 x 10(-8) to 3.19 x 10(-7) micrograms/micrograms total RNA) was greater than in adjacent mucosa (0 to 3.4 x 10(-8) micrograms/micrograms total RNA). This induction of sucrase-isomaltase messenger RNA and enzyme activity was corroborated by immunostaining. Of 30 colon adenocarcinomas examined, 80% were positive for sucrase-isomaltase. In addition, all colon carcinoma metastases examined were positive for sucrase-isomaltase. The staining pattern was distinct and demarcated tumor cells from the surrounding histologically normal tissue. No sucrase-isomaltase staining was seen in normal mucosa from the same patients. With the exception of lung, no sucrase-isomaltase immunostaining was observed in a variety of examined noncolonic adenocarcinomas. Thus, the specificity and ubiquity of sucrase-isomaltase expression in adenocarcinomas of the colon can be exploited to improve the clinical management of this disease. In addition, studies on the structure of the sucrase-isomaltase gene and its regulatory elements should contribute toward understanding the alteration of gene expression by oncogenic transformation of the colonic mucosa.
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PMID:Expression of enzymatically active sucrase-isomaltase is a ubiquitous property of colon adenocarcinomas. 170 85

The intestinal sucrase-isomaltase (SI) complex is a glycoprotein of the small intestine brush border membrane that plays an important role in the final degradation of carbohydrate. To clone the chicken SI, we employed reverse transcriptase polymerase chain reaction (RT-PCR). Agarose gel electrophoresis of the PCR products exhibited one amplified band of approximately 800 bp. The fragment was extracted from the gel and sequenced. The cDNA sequence of the chicken SI is 786 bp in length and exhibits 99% identity at the nucleotide level to the Homo sapiens SI mRNA. Using our cDNA as a probe, Northern analysis revealed a transcript of approximately 6.0 kb in chicken jejunum and ileum tissues.
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PMID:Research notes: Identification and isolation of chicken sucrase-isomaltase cDNA sequence. 946 64

A 303-bp cDNA of intestinal zinc exporter (ZnT1) was isolated from chicken jejunum by reverse transcriptase-polymerase chain reaction and sequenced, and showed 42% homology to Homo sapiens and Rattus novergicus intestinal ZnT1 genes. This specific probe was used to examine the effect of zinc-methionine (ZnMet) administration on the mRNA expression of ZnT1 and on small intestinal development and functionality. In this study, ZnMet was injected into the naturally consumed amniotic fluid of 17-day-old chicken embryos. The ZnT1 gene showed an approximately 200% increase in its mRNA levels from 48 h post-ZnMet injection, as compared to the control. An analysis of the gene expression of the brush-border enzymes and transporters showed increased mRNA expression of sucrase isomaltase, leucine-aminopeptidase, sodium-glucose cotransporter and Na+K+ATPase transporter (Na+K+ATPase) from 48 h post-ZnMet injection, in comparison to controls. Significant increases (P<.05) in the biochemical activity of the brush-border enzymes and transporters, and in jejunal villus surface area were detected from day of hatch (96 h post-ZnMet injection) as compared to controls. These results suggest that ZnMet administration into prenatal intestine via injection into the amniotic fluid enhances intestinal development and improves its functionality.
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PMID:Changes in chicken intestinal zinc exporter mRNA expression and small intestinal functionality following intra-amniotic zinc-methionine administration. 1593 45