Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.1.99.3 (PRE)
 1,923 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have investigated the developmental and tissue specific expression of the human embryonic zeta-globin gene in transgenic mice. A construct containing 550 bp of zeta-globin 5' flanking region, fused to a beta-galactosidase (lacZ) reporter gene and linked to the locus control region (LCR)-like alpha positive regulatory element (alpha PRE) was employed for the production of transgenic mice. Firstly, we compared the number of live born transgenic mice containing this construct to the number of live born transgenic mice containing the entire zeta-globin gene linked to the alpha PRE or the beta LCR. Data showed that 12% of mice generated from eggs injected with zeta-promoter/lacZ/alpha PRE DNA were transgenic compared to only 2% of mice generated from eggs injected with the entire zeta-globin gene linked to the alpha PRE or the beta LCR. The reduced number of live born transgenic mice containing the latter constructs suggests that death of transgenic embryos, possibly due to thalassaemia, may be occurring. X-gal staining of whole embryos containing the lacZ gene revealed that zeta-globin promoter activity was most pronounced at 8.5-9.5 days of development and was restricted to erythroid cells. By 15 days of development, no zeta-globin promoter activity was detected. These results suggest that the alpha PRE can direct high level expression from the zeta-globin promoter and that sequences required for the correct tissue and developmental specific expression of the human zeta-globin gene are present within 550 bp's of 5' flanking region. Sequences within the body of the zeta-globin gene or 3' of the cap site do not appear to be necessary for correct zeta-globin developmental regulation.
 ...
PMID:The developmental regulation of the human zeta-globin gene in transgenic mice employing beta-galactosidase as a reporter gene. 145 28

Members of the human beta-globin gene family are expressed at discrete stages of development and therefore provide an important model system for examining mechanisms of temporal gene regulation. We have previously shown that expression of the embryonic beta-like globin gene (epsilon) is mediated by a complex array of positive and negative upstream control elements. Correct developmental stage- and tissue-specific gene expression is conferred by synergistic interactions between a positive regulatory element (termed epsilon-PRE II) which is active only in embryonic erythroid cells and at least two other regulatory domains upstream of the epsilon-globin gene promoter. A nuclear factor highly enriched in cultured embryonic erythroid cells and in mouse embryonic yolk sac binds to a novel, evolutionarily conserved sequence within epsilon-PRE II. We show here that binding of this factor to the conserved element within epsilon-PRE II is critical for transcriptional activity. Point mutations that interfere with protein binding to epsilon-PRE II abolish transcriptional activation of the constitutive epsilon-globin promoter. Adult erythroid nuclei (from cultured cells or adult mouse liver) also contain a factor that binds to this region, but the complex formed migrates more rapidly during nondenaturing electrophoresis, suggesting either that distinct proteins bind to epsilon-PRE II or that a single protein is differentially modified in these cells in a way that modulates its activity. Several lines of evidence suggest that the binding factors in embryonic and adult erythroid cells are distinguished by posttranscriptional differences.
 ...
PMID:A novel developmental regulatory motif required for stage-specific activation of the epsilon-globin gene and nuclear factor binding in embryonic erythroid cells. 819 19

The stage-specific regulation of mammalian embryonic globin genes has been an experimentally elusive problem, in part because of the developmentally early timing of their expression. We have carried out a systematic analysis of truncation and internal deletion mutations within the 5'-flanking region of the human embryonic beta-like globin gene (epsilon) in erythroid and nonerythroid cell lines. Within a 670-bp region upstream from the constitutive promoter are multiple positive and negative control elements. Of these, a positive regulatory element (epsilon-PRE II) which is active only in embryonic erythroid cells is of particular interest. Remarkably, although it is inactive on its own, in the presence of other sequences located further upstream, it confers tissue- and developmental stage-specific expression on a constitutive epsilon-globin or heterologous promoter. The activity of epsilon-PRE II is also modulated by another positive regulatory domain located further downstream to direct erythroid cell-specific, but little or no embryonic stage-specific, transcription. A nuclear factor highly enriched in embryonic erythroid cells binds specifically within a 19-bp region of epsilon-PRE II. Nuclei from adult erythroid cells also contain a factor that binds to this region but forms a complex of faster electrophoretic mobility. We speculate that interactions between epsilon-PRE II and other upstream control elements play an important role in the developmental regulation of the human embryonic beta-like globin gene.
 ...
PMID:Developmental regulation of the human embryonic beta-like globin gene is mediated by synergistic interactions among multiple tissue- and stage-specific elements. 824 63

The mammalian beta-like globin gene family has served as an important model system for analysis of tissue- and developmental state-specific gene regulation. Although the activities of a number of regulatory proteins have been implicated in the erythroid cell-specific transcription of globin genes, the mechanisms that restrict their expression to discrete stages of development are less well understood. We have previously identified a novel regulatory element (PRE II) upstream from the human embryonic beta-like globin gene (epsilon) that synergizes with other sequences to confer tissue- and stage-specific expression on a minimal epsilon-globin gene promoter in cultured embryonic erythroid cells. Binding of an erythroid nuclear protein (PRE II-binding factor [PRE-IIBF]) to the PRE II control element is required for promoter activation. Here we report on some of the biochemical properties of PREIIBF, including the characterization of its specificity and affinity for DNA. The embryonic and adult forms of PREIIBF recognize their cognate sequences with identical specificities, supporting our earlier conclusion that they are very similar proteins. PREIIBF binds DNA as a single polypeptide with an Mr of approximately 80,000 to 85,000 and introduces a bend into the target DNA molecule. These results suggest a mechanism by which PREIIBF may contribute to the regulation of the embryonic beta-like globin gene within the context of a complex locus.
 ...
PMID:A DNA-bending protein interacts with an essential upstream regulatory element of the human embryonic beta-like globin gene. 862 84

The human embryonic beta-like globin (epsilon-globin) gene is expressed in primitive erythroid cells of the yolk sac during the first few weeks of development. We have previously shown that developmental stage-specific expression of the epsilon-globin gene is mediated by multiple positive and negative regulatory elements upstream of the start of transcription. Of particular interest is one positive regulatory element, PRE II, that works together with other elements (PRE I and PRE V) to confer developmental stage- and/or tissue-specific expression on a minimal promoter. An approximately 85- to 90-kDa PRE II binding factor (PREIIBF) was identified in the nuclei of erythroid cells and shown to bind specifically to a novel 19-bp region within PRE II; binding of this protein to PRE II resulted in bending of the target DNA and was required for promoter activation. In this report, we present the cDNA expression cloning of PREIIBF. The cDNA encodes a previously identified member of the HMG domain family of DNA binding proteins termed SSRP1. By a number of biochemical and immunological criteria, recombinant SSRP1 appears to be identical to the PREII binding factor from erythroid nuclei. A hallmark of HMG domain proteins is their ability to bend their target DNAs; therefore, as we speculated previously, DNA bending by SSRP1/PREIIBF may contribute to the mechanism by which PRE II synergizes with other regulatory elements located upstream and downstream. In contrast with reports from other investigators, we demonstrate that SSRP1 binds DNA with clear sequence specificity. Moreover, we show that SSRP1/PREIIBF lacks a classical activation domain but that binding by this protein to PRE II is required for activation of a minimal promoter in stable erythroid cell lines. These studies provide the first evidence that SSRP1 plays a role in transcriptional regulation. SSRP1/PREIIBF may serve an architectural function by helping to coordinate the assembly of a multiprotein complex required for stage-specific regulation of the human epsilon-globin gene.
 ...
PMID:The HMG domain protein SSRP1/PREIIBF is involved in activation of the human embryonic beta-like globin gene. 956 81