Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The NAC (nitrogen assimilation control) protein from Klebsiella aerogenes is a LysR-like regulator for transcription of several operons involved in nitrogen metabolism, and couples the transcription of these sigma 70-dependent operons to regulation by the sigma 54-dependent NTR system. NAC activates expression of operons (e.g. histidine utilization, hut), allowing use of poor nitrogen sources, and represses expression of operons (e.g. glutamate dehydrogenase, gdh) allowing assimilation of the preferred nitrogen source, ammonium. NAC is both necessary and sufficient to activate transcription, but the expression of the nac gene is totally dependent on the central nitrogen regulatory system (NTR) and RNA polymerase carrying the sigma 54 sigma factor (RNAP sigma 54). Nitrogen starvation signals the NTR system to transcribe nac, and NAC activates the transcription of hut, put (proline utilization), and urease. NAC does not affect the transcription of RNAP sigma 54-dependent operons like ginA or nifLA, which respond directly to the NTR system, but activates transcription of RNAP sigma 70-dependent operons. Thus NAC acts as a bridge between RNAP sigma 70-dependent operons like hut and the RNAP sigma 54-dependent NTR system. The activation of operons like hut by NAC in response to nitrogen starvation is at least superficially similar to their activation by CAP-cAMP in response to carbon and energy starvation.
Mol Microbiol 1991 Nov
PMID:The role of the NAC protein in the nitrogen regulation of Klebsiella aerogenes. 166 20

The nagE operon, encoding the enzyme II specific for N-acetylglucosamine (EIINag), and adjacent DNA from the chromosome of Klebsiella pneumoniae were sequenced and compared with the corresponding sequence from Escherichia coli K12. The deduced EIINag sequences differ in 72 out of 651 amino acids, the K. pneumoniae sequence being three residues longer. The amino acid differences were distributed unevenly, and were most frequent in regions connecting the three functional domains of the protein. In the nagE-nagB intergenic region, two promoter, two operator, and one CAP consensus sequence with regulatory functions were highly conserved. The nag structural genes from both species were very similar (83% DNA similarity; 89% amino acid similarity) except for frequent AT to GC exchanges in the wobble base of codons in K. pneumoniae DNA relative to the E. coli DNA.
Mol Gen Genet 1991 Nov
PMID:Comparison of the sequences of the nagE operons from Klebsiella pneumoniae and Escherichia coli K12: enhanced variability of the enzyme IIN-acetylglucosamine in regions connecting functional domains. 174 34

Expression of the human atrial natriuretic peptide (hANP)gene is controlled by a series of positive and negative cis-acting regulatory elements present in the 5' flanking sequences (5'FS) of the gene. Positive elements located between -1150 and -222, relative to the transcription start site, appear to be responsible for the major portion of ANP gene expression in neonatal rat cardiac atrial cells. While neonatal ventricular cardiocytes, at a qualitative level, seem to employ regulatory signals similar to their atrial counterparts, they do so with reduced efficiency. Expression of the hANP gene in nonmyocardial cells is limited by the presence of silencer elements in the distal (-2593 to -1150) and proximal (-222 to the CAP site) 5'FS. Further characterization of a 64-base pair cardiac-specific element (-410 to -332), described previously, revealed that a core sequence of 40 base pairs is required for functional activity. This core sequence includes a previously defined DNAse-I footprint region flanked by two GC-rich segments arranged in an inverted repeat-like array. These findings suggest that the disparity in atrial vs. ventricular cardiocyte expression of the ANP gene reflects differences that are largely quantitative in nature, while differences in myocardial vs. nonmyocardial cells result from fundamental qualitative differences in the way these cells recognize and use the regulatory elements present within the 5'FS.
Mol Endocrinol 1991 Sep
PMID:Cis-active determinants of cardiac-specific expression in the human atrial natriuretic peptide gene. 183 91

The divergent nagE-BACD operons located at 15.5 min on the Escherichia coli chromosome encode genes involved in the uptake and metabolism of N-acetylglucosamine. The start sites of the divergent transcripts are separated by 133 base-pairs (bp). A repressor protein for the regulon is encoded by the gene nagC, one of the genes of the nagBACD operon. Strains overproducing the NagC protein have been used to investigate the binding of repressor to the intergenic nagE-B regulatory region. Two binding sites have been detected, overlapping the promoters of the nagE and nagB genes. NagC binding produces a series of DNase I hypersensitive sites separated by 9 to 11 bp in the region between the two NagC binding sites, supporting a model where the NagC proteins bind co-operatively to these two sites on the DNA and interact to form a DNA loop. A strong CAP binding site exists between the two operator sites. It is located at -61.5 and -71.5 relative to the nagE and nagB transcription start sites. CAP and NagC can bind simultaneously and produce a complex more stable than the binary NagC-DNA complex. In addition NagC and CAP binding sites have been found upstream from the manXYZ operon. Although the sites exhibit a similar organization there is no evidence for formation of a DNA loop in this operon.
J Mol Biol 1991 Feb 20
PMID:CAP and Nag repressor binding to the regulatory regions of the nagE-B and manX genes of Escherichia coli. 184 37

Lac repressor (LacR) is a helix-turn-helix motif sequence-specific DNA binding protein. Based on proton NMR spectroscopic investigations, Kaptein and co-workers have proposed that the helix-turn-helix motif of LacR binds to DNA in an orientation opposite to that of the helix-turn-helix motifs of lambda repressor, lambda cro, 434 repressor, 434 cro, and CAP [Boelens, R., Scheek, R., van Boom, J. and Kaptein, R., J. Mol. Biol. 193, 1987, 213-216]. In the present work, we have determined the orientation of the helix-turn-helix motif of LacR in the LacR-DNA complex by the affinity cleaving method. The DNA cleaving moiety EDTA.Fe was attached to the N-terminus of a 56-residue synthetic protein corresponding to the DNA binding domain of LacR. We have formed the complex between the modified protein and the left DNA half site for LacR. The locations of the resulting DNA cleavage positions relative to the left DNA half site provide strong support for the proposal of Kaptein and co-workers.
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PMID:Orientation of the Lac repressor DNA binding domain in complex with the left lac operator half site characterized by affinity cleaving. 192 7

CAP, a protein from Saccharomyces cerevisiae that copurifies with adenylyl cyclase, appears to be required for yeast cells to be fully responsive to RAS proteins. CAP also appears to be required for normal cell morphology and responsiveness to nutrient deprivation and excess. We describe here a molecular and phenotypic analysis of the CAP protein. The N-terminal domain is necessary and sufficient for cellular response to activated RAS protein, while the C-terminal domain is necessary and sufficient for normal cellular morphology and responses to nutrient extremes. Thus, CAP is a novel example of a bifunctional component involved in the regulation of diverse signal transduction pathways.
Mol Cell Biol 1991 Mar
PMID:CAP is a bifunctional component of the Saccharomyces cerevisiae adenylyl cyclase complex. 199 90

The pro-opiomelanocortin gene is widely expressed in human tissues, although both transcriptional initiation sites and regulation appear to be tissue specific. In order to determine how promoter and enhancer choice is effected, we have studied the methylation pattern of the gene in a number of normal tissues, tumours and cell lines. Variability of this pattern was observed in the 5'-flanking DNA, particularly at the HpaII site located at -304 bp upstream from the pituitary CAP site. This site was generally methylated in tissues likely to express the predominant extrapituitary (800 nucleotide) message, while in tissues known to express the normal pituitary (1150 nucleotide) message and longer species, a tendency towards undermethylation was observed. Although the sites at which variable methylation occurs did not correspond to established binding sites for regulatory proteins, many of these regions remain to be determined and thus it is possible that methylation may be influential in the tissue-specific regulation of this gene.
J Mol Endocrinol 1991 Feb
PMID:Variable methylation of the 5'-flanking DNA of the human pro-opiomelanocortin gene. 201 57

Interaction of cloned yeast, drosophila, and human transcription factor IID (yTFIID, dTFIID, and hTFIID, respectively) with the adenovirus 2 major late promoter (Ad2 MLP) confers a more limited pattern of DNase I protection than that obtained using highly purified native hTFIID (Hahn, S., Buratowski, S., Sharp, P. A. and Guarente, L. (1989) EMBO J. 8, 3379-3382; Van Dyke, M. W., and Sawadogo, M. (1990) Mol. Cell. Biol. 10, 3415-3420; Horikoshi, M., Wang, C.K., Fujii, H., Cromlish, J.A., Weil, P.A., and Roeder, R.G. (1989) Nature 341, 299-303; Peterson, M. G., Tanese, N., Pugh, B.F., and Tjian, R. (1990) Science 248, 1625-1630; Hoey, T., Dynlacht, B. D., Peterson, M.G., Pugh, B.F., and Tjian, R. (1990) Cell 61, 1179-1186). Since the mass of the cloned TFIIDs is considerably less than that of native hTFIID (27-38 kDa versus 120-140 kDa), it is considered likely that native hTFIID exists as a mixed heterodimer. We have recently identified, purified, and characterized a novel transcription factor that binds to the CAP site region (+1 to +23) of the Ad2 MLP. This CAP site binding factor, designated CBF, is required for optimal transcriptional activity. We now show that when bound to the Ad2 MLP, yTFIID and CBF interact to generate the extended pattern of DNase I protection conferred by native hTFIID. In addition, bound yTFIID and CBF interact such that the stability of the complex exceeds that of each factor bound alone. We also demonstrate the existence in nuclear extracts of a hTFIID and CBF heterodimer by the electrophoretic mobility shift analysis. CBF, therefore, may represent the first identified member of a large family of gene-specific TFIID-associated factors that are required for the regulated gene-specific expression of TFIID activity.
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PMID:Interaction of CAP sequence site binding factor and transcription factor IID preceding and following binding to the adenovirus 2 major late promoter. 204 Jun 15

Expression of the TSH beta subunit gene is restricted to the thyrotroph cells of the anterior pituitary. Previously we identified several AT-rich DNA elements within the murine (m) TSH beta 5'-flanking region, denoted as D1 (-253 to -227), P4 (-142 to -131), P3 (-126 to -112), P2 (-106 to -98), and P1 (-76 to -68) which bind thyrotroph-specific factor(s). These sites are related to, but distinct from GHF-1 and LSF-1 binding sites, which restrict GH and PRL gene expression to pituitary somatotrophs and lactotrophs, respectively. To determine whether different pituitary cell types contain related factors capable of activating the mTSH beta promoter, cell-free transcription studies were performed using extracts from GH4 rat pituitary somatomammotroph cells. AI-through the endogenous mTSH beta gene is not expressed in GH4 cells, in vitro transcription of the mTSH beta promoter, normalized to the Rous sarcoma virus internal control, revealed faithful transcription initiation from the authentic mTSH beta CAP sites in GH4 but not in HeLa cell extracts. Cell-free transcription analysis of mTSH beta 5'-deletion mutants revealed consistent promoter activity with deletion to position -46 but complete loss of activity when deleted to position -9. To better define the specific factors in pituitary somatomammotrophs which interact with and activate the mTSH beta promoter, DNase I protection and gel-shift studies were performed using extracts from GC rat pituitary somatomammotroph cells and DNA affinity-purified lactotroph-specific transcription factor, LSF-1, required for rat PRL promoter activity, and purified from GC cells. These cells contain a factor(s) which binds to thyrotroph-specific elements of the mTSH beta promoter. These studies also show that LSF-1 binds the D1 and proximal thyrotroph-specific elements of the mTSH beta promoter and is capable of reconstituting the trans-activation of the mTSH beta promoter in HeLa nonpituitary cell extracts in vitro. Conversely, nuclear factors present in TtT-97 murine thyrotrophs bind the proximal lactotroph-specific elements on the rPRL promoter. This in vitro transcription assay provides a means to biochemically dissect the trans-activation of the mTSH beta promoter and to determine the functional overlap of distinct pituitary cell-specific factors in regulating GH, PRL, and TSH beta gene expression.
Mol Endocrinol 1990 Dec
PMID:Activation of the murine thyrotropin beta-subunit promoter by GH4 rat pituitary cell-free extracts. 208 87

The availability of the amino acid sequence for nine different mammalian P1 family protamines and the revised amino acid sequence of the chicken protamine galline (Oliva and Dixon 1989) reveals a much close relationship between mammalian and avian protamines than was previously thought (Nakano et al. 1976). Dot matrix analysis of all protamine genes for which genomic DNA or cDNA sequence is available reveals both marked sequence similarities in the mammalian protamine gene family and internal repeated sequences in the chicken protamine gene. The detailed alignments of the cis-acting regulatory DNA sequences shows several consensus sequence patterns, particularly the conservation of a cAMP response element (CRE) in all the protamine genes and of the regions flanking the TATA box, CAP site, N-terminal coding region, and polyadenylation signal. In addition we have found a high frequency of the CA dinucleotide immediately adjacent to the CRE element of both the protamine genes and the testis transition proteins, a feature not present in other genes, which suggests the existence of an extended CRE motif involved in the coordinate expression of protamine and transition protein genes during spermatogenesis. Overall these findings suggest the existence of an avian-mammalian P1 protamine gene line and are discussed in the context of different hypotheses for protamine gene evolution and regulation.
J Mol Evol 1990 Apr
PMID:Vertebrate protamine gene evolution I. Sequence alignments and gene structure. 211 48


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