Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

hsp30 is a small heat shock protein of Neurospora crassa which earlier studies suggested may associate with mitochondria during cellular heat shock. We show here that the association of hsp30 with mitochondria is reversible and that hsp30 dissociates after cells are returned to normal temperature. We sequenced the gene for hsp30 and defined its transcript by S1 nuclease analysis and cDNA sequencing. The gene apparently is present in the genome as a single copy, and it contains no introns. The encoded 25.3-kDa peptide is related to other small heat shock proteins, especially those from green plants. According to its deduced sequence, hsp30 can form two strongly amphiphilic alpha-helices, including one at its amino terminus. In binding assays, in vitro synthesized hsp30 bound strongly to mitochondria isolated from heat-shocked cells but not to mitochondria prepared from cells incubated at normal temperature. A mutant hsp30 peptide, deleted in the amino-terminal amphiphilic helix, bound more avidly than the full-length hsp30 to mitochondria isolated from heat-shocked cells and exhibited less stringent requirements for binding. The mutant peptide also showed strong affinity for mitochondria isolated from unstressed cells.
J Biol Chem 1990 Sep 15
PMID:Gene sequence and analysis of hsp30, a small heat shock protein of Neurospora crassa which associates with mitochondria. 214 84

Cardiac hypertrophy is associated with qualitative as well as quantitative changes in myocardial cells. To analyze the molecular basis of isozymic transitions of cardiac myosins in response to pressure overload, we have constructed and characterized two types of myosin heavy chain (MHC) cDNA clones, specifying alpha- and beta-MHCs, and two types of myosin alkali light chain cDNA clones, complementary to atrial type (ALC1) and ventricular type (VLC1) mRNAs from a human fetal heart cDNA library. Using the S1 nuclease mapping procedure, we showed that the MCH isozymic transitions from alpha- to beta-MHC in the pressure overloaded atria are produced by changes in the relative level of alpha- and beta-MHC gene expression. In addition, we observed that the expression of VLC1 gene is also induced in the atria subjected to severe pressure overload. Thus, it appears that the increased expression of VLC1 gene, together with the isogene switch from alpha- to beta-MHC gene, may participate in the adaptation of myocardium to new functional requirement. Then, to get a better understanding of the genetic mechanisms involved in the regulation of isogene expression, we have isolated and sequenced genomic clone for VLC1 isoform. Sequence analysis has identified multiple potential cis regulatory elements within a 686-bp upstream region. This region includes 28-bp alternating purine/pyrimidine sequences and two segment exhibiting homology to consensus sequence proposed for viral and cellular enhancer elements. In particular, a comparison of the VLC1 upstream gene sequence with those available for several muscle-specific genes revealed that CC(A + T-rich)6GG elements and CATTCCT sequence are conserved. These results suggested that CArG box (-96 to -87) has an important role in the positive regulation of the VLC1 gene and this element may be involved in the co-regulation of VLC1 and cardiac alpha-actin genes.
Jpn Circ J 1990 Sep
PMID:The myosin gene switching in human cardiac hypertrophy. 214 55

The major 64-kDa structural protein of human cytomegalovirus (pp64) was isolated from a guanidinium chloride extract of the virions and dense bodies of HCMV (Towne) by reverse-phase HPLC. Purified pp64 was reduced and alkylated followed by digestion with trypsin. The molecular mass of each of the tryptic peptides was determined by fast atom bombardment/mass spectrometry and compared with the predicted molecular mass of the fragments deduced from the corresponding DNA-derived peptide sequence of pp65 from HCMV (AD169). Microsequence analysis was employed to confirm selected peptides. Results of protein sequence analysis of pp64 from HCMV (Towne) are in complete agreement with the DNA-derived protein sequence of pp65 predicted for HCMV (AD169) with the following exceptions and modifications. The protein isolated from HCMV (Towne) was found to contain an Ala at position 448 instead of Ser448 reported for the protein from HCMV (AD169). We also identified Ser472 as a site of phosphorylation in pp64 from HCMV (Towne). Finally, on the basis of the sequence of HCMV (AD169) DNA fragment encoding the matrix protein and on S1 nuclease protection analysis, it has been predicted that one version of the matrix protein (possibly the lower matrix protein, Mr 65K) is encoded by an mRNA that is formed through splicing of a short intron. However, we have obtained peptides that contain sequences spanning through the splice-junction region, suggesting that in HCMV (Towne), the matrix protein is encoded by an unspliced message.
Virology 1990 Sep
PMID:Structural analysis of a 64-kDa major structural protein of human cytomegalovirus (Towne): identification of a phosphorylation site and comparison to pp65 of HCMV (AD169). 216 61

Retinoic acid (RA) induced differentiation of SH-SY5Y neuroblastoma cells is associated with more than a tenfold induction of total Alzheimer's disease beta A4 amyloid protein precursor (APP) mRNA as analyzed by Northern blot hybridisation. S1 nuclease protection experiments reveal that the splicing pattern of these differentiated cells is altered in favor of APP695 mRNA, coding for the shortest amyloidogenic beta A4 amyloid precursor protein. Induction of differentiation of SH-SY5Y cells with NGF leads to a fivefold increase of total APP mRNA without change in the splicing pattern. This suggests that RA but not NGF induces factor(s) which are responsible for an APP hnRNA splicing favoring APP695 mRNA.
FEBS Lett 1990 Sep 03
PMID:Retinoic acid induced differentiated neuroblastoma cells show increased expression of the beta A4 amyloid gene of Alzheimer's disease and an altered splicing pattern. 220 13

In experiments designed to measure radiation-induced DNA damage using the DNA unwinding-hydroxyapatite chromatography technique, we observed that under some experimental conditions a significant proportion of the test DNA became tightly bound to the hydroxyapatite (HA) and could not be released even with a high concentration of phosphate buffer. Approximately 5-10% of DNA from unirradiated cells binds to the HA. With increasing radiation doses in air, the fraction of bound DNA increases, reaching about 30% at about 35 Gy. The binding exhibits many of the characteristics of a radiation-induced cell lesion: the proportion of DNA retained by the HA is less when cells are irradiated under hypoxic conditions or in the presence of the thiol radioprotector dithiothreitol; and the binding decreases when an incubation period is allowed between irradiation and harvest of the cells for assay. Studies to determine the nature of the lesion responsible for the binding demonstrated that lesion production requires a component found in cells since no binding was observed with irradiated isolated DNA or nuclear matrix; the binding is not a result of the production of DNA-protein crosslinks; and the bound DNA is single-stranded, based on its sensitivity to nuclease S1. Because of the dose dependence of the binding of DNA to HA, the slopes of the dose-response curves for DNA damage determined with this assay depend on the method used to calculate the fraction of double-stranded DNA. Our demonstration that the bound DNA is single-stranded guides the choice of the method for data analysis.
Radiat Res 1990 Sep
PMID:Radiation-induced binding of DNA from irradiated mammalian cells to hydroxyapatite columns. 221 24

Responses to androgen vary widely among prostate cancers and prostatic carcinoma cell lines. We have explored the basis for this heterogeneity by examining the levels of androgen receptor expression in a prostate carcinoma cell line (LNCaP) that expresses the androgen receptor and two prostate carcinoma cell lines that do not contain detectable androgen receptor. We find that while the LNCaP cell line contains high levels of both the androgen receptor protein and mRNA, the receptor-negative cell lines DU-145 and PC-3 do not express androgen receptor protein as detected by immunoblotting or mRNA as detected by Northern analysis or S1 nuclease protection. These results indicate that the absence of androgen receptor expression in the androgen receptor-negative cell lines is caused by diminished androgen receptor mRNA levels. Genomic Southern analysis indicates that the differences in androgen receptor expression in each of these cell lines is not associated with detectable alterations in the structure of the androgen receptor gene.
Cancer Res 1990 Sep 01
PMID:Androgen receptor gene expression in human prostate carcinoma cell lines. 238 43

The transcription of omp1, the gene encoding the major outer membrane protein, was studied for two strains of Chlamydia psittaci, guinea pig inclusion conjunctivitis (GPIC) and mouse pneumonitis (Mn). The transcriptional initiation sites for the omp1 of each strain were mapped by S1 nuclease and primer extension analyses. Three different sizes of omp1 transcripts were observed for GPIC and four were observed for Mn. The production of these transcripts appeared to be the consequence of multiple tandem promoters. The order in which the omp1 RNA transcripts appeared during the growth cycle of the C. psittaci strains was found to differ from that of C. trachomatis.
Infect Immun 1990 Sep
PMID:Multiple tandem promoters of the major outer membrane protein gene (omp1) of Chlamydia psittaci. 238 24

Nucleolin, a eukaryotic nucleolar phosphoprotein, is involved in the synthesis and maturation of ribosomes. To characterize the genomic organization and regulatory sequences of this gene, two overlapping lambda clones containing the human nucleolin gene plus flanking regions were isolated from a genomic library using human nucleolin cDNA. Southern blots of genomic DNA from human, several mammals, chicken, and yeast revealed that the nucleolin gene is well conserved across these species. The gene consists of 14 exons with 13 intervening sequences and spans approximately 11 kilobases of DNA. Analysis of the splice junctions indicated that the amino-terminal domain and the four RNA binding domains plus the nuclear localization signal are split into adjacent exons. Sequences from the 5'-flanking and the first intron contain a high content of GC residues which is consistent with nucleolin being a "housekeeping" gene. Promoter elements include an atypical TATA box (GTTA), one CCAAT box much further from the initiation site, three reverse compliments of CCAAT (ATTGG), and two pyrimidine-rich nucleotide stretches. In addition, this region and the first intron contain numerous potential Sp1, GCF, CRE-fos, GCN, AP-1, AP-2, UCE, and sequences similar to the glucocorticoid receptor binding site. The transcription start site was determined by primer extension and S1 nuclease mapping of RNA from human liver. One Kpn and three Alu repeats were found within two of the middle introns. The 3'-untranslated portion of the gene contains five homology blocks in a 100-base pair region that are highly conserved among human, mouse, and hamster genomes. Finally, we have determined that the human nucleolin gene is located on chromosome 2q12-qter and is present at one copy per haploid genome. A restriction fragment length polymorphism with EcoRI has been detected in the gene.
J Biol Chem 1990 Sep 05
PMID:Genomic organization and chromosomal localization of the human nucleolin gene. 239 7

Fast skeletal muscle troponin C (sTnC) is the calcium-binding subunit of the myofibrillar thin filament that regulates excitation-contraction coupling. Utilizing a polymerase chain reaction cloning strategy, we have isolated cDNA clones encoding murine sTnC. The 160-amino acid sTnC protein shares 70% amino acid sequence identity with the slow/cardiac isoform of troponin C (cTnC). However, three areas of significant sequence divergence were identified. Southern blot analyses demonstrated that murine sTnC is encoded by a single copy gene that is distinct from that which encodes cTnC. Northern blot analyses showed that the sTnC gene is expressed exclusively in skeletal muscle (extensor digitorum and anterior tibialis) and not in neonatal or adult heart, brain, kidney, liver, lung, or testes. Studies of the murine C2C12 myoblast cell line demonstrated that sTnC gene expression is developmentally regulated during the differentiation of these myoblasts into myotubes. A full-length murine sTnC genomic clone was isolated and characterized by DNA sequence, primer extension, and S1 nuclease protection analyses. The sTnC gene is composed of six exons spanning 2.6 kilobase pairs of genomic DNA. Although the introns do not divide the gene into functional domains, the intron-exon borders are nearly identical to those of the other members of the troponin C multigene family. Transient transfection assays using chloramphenicol acetyltransferase reporter plasmids demonstrated that the sTnC promoter alone is relatively inactive in muscle cells and that high level sTnC gene expression in these cells is controlled by a potent transcriptional enhancer element located within the first intron of the gene. In additional transfection experiments, the sTnC enhancer was shown to display three important biological activities. (i) It was required for high level transcription from the sTnC promoter in muscle cells; (ii) its activity was muscle cell specific; and (iii) its activity was developmentally regulated during the differentiation of C2C12 myoblasts to myotubes. Taken together, these data define the sTnC gene as an excellent model system for studies of developmentally regulated gene expression in skeletal muscle.
J Biol Chem 1990 Sep 15
PMID:The structure and regulation of expression of the murine fast skeletal troponin C gene. Identification of a developmentally regulated, muscle-specific transcriptional enhancer. 239 55

An efficient cell-free transcription system was developed from the extract of BmN cells established from an ovarian tissue of the silkworm, Bombyx mori. The cloned genes coding for major plasma proteins of B. mori including SP 1, SP 2 and 30K protein, were faithfully and efficiently transcribed in the extract prepared from BmN cells. The S1 nuclease mapping and primer extension analyses demonstrated that the transcription initiation site recognized in vitro is identical to that which functions in vivo. The transcription assay reconstituted from the fractionated BmN cell extract revealed that at least four protein factors are required for accurate transcription of the SP 1 and adenovirus major late genes. The results of in vitro transcription experiments employing a series of the 5' deleted mutant templates of the SP 1 gene indicated that partial deletion of the TATA box results in considerable loss of faithful transcript, while complete removal of the TATA-sequence totally abolishes the transcript. These observations suggest that the promoter element essential for transcription in cell-free systems is located in a region between nucleotide positions -44 and +16 of the SP 1 gene.
Biochim Biophys Acta 1990 Sep 10
PMID:In vitro transcription of the plasma protein genes of Bombyx mori. 240 Jul 86


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>