Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Enhancers, cis-acting transcriptional control elements have been described in both viral and cellular genes. They influence transcription in a quantitative fashion, act over relatively large distances (several kilobases, kb) and behave independently of their position and orientation. Enhancers have been described in immunoglobulin, chymotrypsin and insulin genes. They bear little homology with each other except for an 8-base pair (bp) 'consensus' core element, GTGGAAATTTG (refs 10, 11), but even this element is sometimes non-homologous. I have searched for such elements in the human antithrombin III (AT-III) gene. AT-III is an important coagulation protein which inactivates thrombin. It is produced by the liver and, to a lesser extent, by the kidney. Here, I report that the 5' flanking region of the AT-III gene encodes a segment homologous with the enhancer containing the joining-constant kappa (J kappa-C kappa) intron of immunoglobulin kappa-chain genes. This extensive homology suggests the existence of regulatory factors that recognize common DNA sequences in lymphoid tissues and in those which express AT-III.
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PMID:Relationship between an enhancer element in the human antithrombin III gene and an immunoglobulin light-chain gene enhancer. 299 11

Transfection of genes into tissue culture cell lines has demonstrated that relatively short DNA sequences can allow expression of immunoglobulin, insulin and chymotrypsin genes in their appropriate cell types. A definitive test of cell-specific gene expression, however, requires testing genes in every possible cell type, an experiment performed easily by introducing the gene in question into the germ line of an animal. Transfer of intact genes into mice has demonstrated that a mouse immunoglobulin kappa gene is expressed specifically in B lymphocytes, a rat elastase I gene is expressed specifically in pancreas and a chicken transferrin gene is expressed preferentially in liver. Mouse metallothionein-growth hormone fusion genes introduced into mice are preferentially expressed in the liver, consistent with the expression of endogenous metallothionein genes, but initial experiments with beta-globin genes have not revealed proper regulation. To identify the DNA elements required for pancreas-specific expression of the rat elastase I gene, we joined the 5'-flanking region of this gene to the human growth hormone (hGH) structural gene and introduced the fusion gene into mice. Here we demonstrate that a fusion gene containing only 213 base pairs (bp) of elastase I gene sequence directs expression of hGH in pancreatic acinar cells.
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PMID:Specific expression of an elastase-human growth hormone fusion gene in pancreatic acinar cells of transgenic mice. 384 51