PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “sequencing libraries”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,567 records · Page 87Linked to original sources

Isolation and characterization of cDNA clones encoding ADP-glucose pyrophosphorylase (AGPase) large and small subunits from chickpea (Cicer arietinum L.).

Four cDNA clones encoding two large subunits and two small subunits of the starch regulatory enzyme ADP-glucose pyrophosphorylase (AGPase) were isolated from a chickpea (Cicer arietinum L.) stem cDNA library. DNA sequence and Southern blot analyses of these clones, designated CagpL1, CagpL2 (large subunits) and CagpS1 and CagpS2 (small subunits), revealed that these isoforms represented different AGPase large and small subunits. RNA expression analysis indicated that CagpL1 was expressed strongly in leaves with reduced expression in the stem. No detectable expression was observed in seeds and roots. CagpL2 was expressed moderately in seeds followed by weak expression in leaves, stems and roots. Similar analysis showed that CagpS1 and CagpS2 displayed a spatial expression pattern similar to that observed for CagpL2 with the exception that CagpS1 showed a much higher expression in seeds than CagpS2. The spatial expression patterns of these different AGPase subunit sequences indicate that different AGPase isoforms are used to control starch biosynthesis in different organs during chickpea development.

Amino Acid Sequence↗

Linkage and cytogenetic mapping of a CAG repeat containing human cDNA to 3p24.2-p22.

A trinucleotide (CAG)n repeat containing cDNA was isolated from a human cDNA library and sequenced. The locus was mapped by linkage analysis in the CEPH families and by cytogenetic analysis to 3p24.2-p22. We have additionally excluded this gene as a candidate for small cell lung carcinoma by the analysis of cell lines carrying homozygous deletions for the 3p chromosomal region.

Chromosome Mapping↗

Two light-responsive elements of pea chloroplastic fructose-1,6-bisphosphatase gene involved in the red-light-specific gene expression in transgenic tobaccos.

The pea chloroplast fructose-1,6-bisphosphatase (FBPase) gene was cloned from a pea genomic library and sequenced. The gene contained three introns and four exons. Both in vitro and in vivo analyses of the promoter region of the gene were carried out simultaneously to elucidate the mechanisms of light-mediated gene expression. Two light-responsive elements were identified in gel mobility shift assays: a GT-1-like sequence for the binding of a GT-1-like factor (termed pea factor 1; PF1) and a binding site for a dark-specific factor (termed pea factor 2; PF2). The binding affinity of PF1 was higher in light-grown peas than in dark-grown peas and was affected by phosphorylation. The binding site was located at nucleotides (nt) -326 to -341. PF2 binding was dark-specific and the binding region was located upstream of the PF1-binding site (nt -492 to -412). In vivo experiments with transgenic tobacco plants suggested that the region between nt -411 and -272 contained a PF1-binding site that promoted light-mediated expression of the pea chloroplast FBPase. In contrast, the 81-bp region between nt -492 and -412, which is located further upstream than the PF1-binding site, negatively regulated light-mediated expression of FBPase. Moreover, activation of gene expression by the region (nt -411 to -272) contained a PF1-binding site that was sensitive to red-light irradiation, suggesting that the expression of the chloroplast FBPase was regulated by the phytochrome system. Interestingly, the binding region for the dark-specific factor (PF2; nt -492 to -412) not only repressed gene expression in the dark, but also acted as a light-dependent activating element of the chloroplast FBPase gene.

Base Sequence↗

Cloning and expression of cDNA for a newly identified isozyme of bovine liver 3-hydroxyacyl-CoA dehydrogenase and its import into mitochondria.

cDNA for a heretofore undescribed mitochondrial 3-hydroxyacyl-CoA dehydrogenase, designated as the type II enzyme with different molecular and catalytic properties, compared to those of the classical mitochondrial beta-oxidation enzyme (type I enzyme), was cloned from a bovine liver cDNA library. Nucleotide sequence of the cDNA encoded 261 amino acids with a subunit molecular weight of 27,140. The deduced primary structure of the type II enzyme showed no significant homology to the reported amino acid sequence of the classical 3-hydroxyacyl-CoA dehydrogenases. On SDS-PAGE, no differences in subunit molecular weights were observed among the in vitro translation products, the recombinant type II enzyme produced in Escherichia coli and the purified enzyme. NH2-terminal and COOH-terminal amino acid sequence analysis of the purified type II enzyme revealed that the mature enzyme had not been proteolytically processed. The in vitro translation products of the type II enzyme were efficiently incorporated into isolated rat liver mitochondria, without changes in size, thereby suggesting that unlike other mitochondrial enzymes of fatty acid beta-oxidation, the type II enzyme had no cleavable signal peptide upon import into mitochondria.

3-Hydroxyacyl CoA Dehydrogenases↗

Molecular cloning and functional expression of chicken luteinizing hormone receptor.

A complementary DNA for chicken luteinizing hormone (LH) receptor containing the entire coding region was isolated from chicken F1 granulosa cell cDNA library. Nucleotide sequence analysis revealed that there are characteristic GC-rich regions around the N-terminal part. Chicken LH receptor consists of a 19-residue signal peptide, a 366-residue extracellular domain, a 267-residue region containing seven transmembrane segments, and a 76-residue cytoplasmic C-terminal tail. The deduced amino acid sequence of the chicken LH receptor shares 67%, 69%, and 69% identity with the human, rat and porcine LH receptor sequences, respectively, and 51% with chicken FSH receptor. However, an insertion of about 30 amino acid residues is found in chicken LH receptor in the extracellular domain about 44 amino acid residues upstream of the first transmembrane segment. In addition, alternative splicing seems likely to occur at the point where the insertion starts (nucleotide position 933), resulting in the truncated forms of chicken LH receptor with only the extracellular domain. Northern blot analysis revealed the presence of multiple transcripts of LH receptor, a major 3.0-kb and minor 7-kb and 1.5-kb bands, in chicken F1 to F3 granulosa cells. The full length chicken LH receptor cDNA was transiently expressed in COS-7 cells and the transfected cells displayed a concentration-dependent increase in cAMP production when exposed to varying concentrations of chicken LH. This clearly indicates that the cloned cDNA encodes a functional chicken LH receptor protein.

Amino Acid Sequence↗

Rat nurr1 is prominently expressed in perirhinal cortex, and differentially induced in the hippocampal dentate gyrus by electroconvulsive vs. kindled seizures.

We isolated a rat orphan nuclear hormone receptor from a brain cortex cDNA library. The sequence of the cDNA insert was 2154 bp with an open reading frame of 1794 bp encoding a putative protein of 598 amino acids and predicted molecular mass of 65 kDa. The deduced amino acid sequence showed a strong homology to the mouse nurr1 and human NOT1 orphan nuclear hormone receptors of the NGFI-B/nur77/NAK1 gene subfamily. We refer to this rat clone as r-nurr1. Northern blot analysis showed that r-nurr1 mRNA was highly expressed in the brain and moderately in the lung as a 4.0 kb transcript. A smaller transcript of 2.5 kb was also detected in the testes. The level of r-nurr1 transcript in the heart, skeletal muscle, liver, kidney and spleen was marginal. In situ hybridization showed that r-nurr1 mRNA was constitutively expressed in various regions of the CNS, particularly in the deeper layers (IV to VI) of the perirhinal cortex and area 2 of parietal cortex. We further evaluated the modulation of r-nurr1 expression in CNS by an electroconvulsive seizure (ECS) and by an amgydala-kindled seizure. A single ECS administered via earclip electrodes induced a rapid and transient increase of r-nurr1 mRNA in the granule cells of the dentate gyrus, being significant at 15 min after the seizure, maximal approximately 1 h and back to baseline at 4 h. The amygdala kindled seizure revealed a less robust and restricted nurr-1 induction in the CNS, as only two of the four kindled animals showed a unilateral induction of nurr1 mRNA in the dentate gyrus. These results suggest that r-nurr1 is an immediate-early gene that is differentially induced by ECS vs. kindled seizures. In addition, as r-nurr1 is prominently expressed in the specific brain sites associated with memory acquisition and consolidation, it may play a role in memory processing.

Animals↗

Regulation of human cbfa1 gene transcription in osteoblasts by selective estrogen receptor modulators (SERMs).

Cbfa1, a transcription factor critical for bone formation, plays a key role in osteoblast recruitment and differentiation. We have cloned and characterized a 3.0 KB 5'-flanking region of the human cbfa1 gene isolated from a P1 human genomic library. DNA sequencing revealed several known canonical nuclear transcription factor binding sites, including two AP1 and six OSE2 binding sites in the proximal promoter region. Although no estrogen (E2)-response element (ERE) binding sites were identified, E2 has been shown to regulate gene activity via AP1 promoter sites. We examined the effect of selective estrogen receptor modulators (SERMs) on human cbfa1 gene promoter activity using cell-based luciferase reporter transcriptional assays. Three characterized SERMs, tamoxifen, raloxifene, and ICI 178,180, all upregulated cbfa1-luciferase (cbfa1Luc) gene activity 5- to 10-fold in a dose-dependent manner. This effect was mediated by both ER alpha and ER beta. Mutational analysis demonstrated that the minimal promoter region for basal of SERM-activated transcription was mapped to adjacent AP1-like and OSE2 binding sites within -93 and +7 of the transcription start condon. Further, electrophoretic mobility shift assays (EMSAs) demonstrate that ICI 178,180 increased binding of AP1 and OSE2 site by ER alpha and cbfa1, respectively. These studies suggest that SERMs can modulate bone-specific cbfa1 gene expression in a human osteosarcoma cell line.

Base Sequence↗

Characterization and chromosomal mapping of a human Necdin pseudogene.

The necdin gene is expressed predominantly in postmitotic neurons and encodes a growth suppressor that interacts with the transcription factors E2F1 and p53. Human necdin gene (NDN) is maternally imprinted and located in Prader-Willi syndrome deletion region 15q11.2-q12. We isolated an NDN homologous sequence from a human genomic DNA library. The homologous sequence is overall 83% identical with necdin cDNA sequence, and possesses a short poly(A) stretch at the 3' end and direct repeats at both ends. Expression of the homologous sequence, which lacks a 5' promoter sequence, was undetected in cultured human cell lines. We mapped this sequence to chromosome 12q14-q21.1 by fluorescence in situ hybridization. These characteristics of the NDN-homologous sequence are consistent with those of processed pseudogenes. The information about the necdin pseudogene in the human genome will be useful for genetic studies on NDN-associated neurogenic disorders.

Base Sequence↗

Analysis of the pobA and pobR genes controlling expression of p-hydroxybenzoate hydroxylase in Azotobacter chroococcum.

We report the cloning and analysis of a gene and its cognate regulatory element from a member of the Azotobacteriaceae which are involved in the breakdown of an aromatic compound. The genes from Azotobacter chroococcum encoding p-hydroxybenzoate hydroxylase (pobA) and its regulatory protein (pobR) were cloned from a genomic library and sequenced. Sequence analysis of pobA revealed homology with other bacterial p-hydroxybenzoate hydroxylase enzymes. Residues essential to the structure and function of the enzyme have been conserved. The pobR gene encodes a DNA binding regulatory protein with similarity to proteins from the AraC/XylS family of transcriptional activators. A fragment containing both pobA and pobR was cloned into pUC19 and p-hydroxybenzoate hydroxylase activity was induced in Escherichia coli by the addition of p-hydroxybenzoate. A frame-shift mutation introduced into the pobR gene prevented expression of p-hydroxybenzoate hydroxylase, indicating that PobR is the protein required for transcription of pobA. Interestingly, A. chroococcum PobR has no homology to the PobR protein that is the transcriptional activator of pobA in Acinetobacter strain ADP1, a protein that is homologous to the IclR family of transcriptional regulators. However, PobR from A. chroococcum is homologous to several other proteins, suggesting that these proteins will also function as transcriptional activators of pobA.

4-Hydroxybenzoate-3-Monooxygenase↗

Cloning and expression of the cDNA for rat NAD+-dependent 15-hydroxyprostaglandin dehydrogenase.

The cDNA for rat NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) was cloned from an intestinal cDNA library. The sequence of this cDNA was found to be identical to that of the reverse transcription-polymerase chain reaction (RT-PCR) product obtained using rat lung RNA as a template. The cDNA contains a 798-bp open reading frame that codes for a protein of 266 amino acids (M(r) 28,775) which shares 88.7% identity with the human 15-PGDH and 92.1% identity with the mouse 15-PGDH protein. The regions that are believed to be the NAD+ binding domain and the active site are conserved in the enzymes from the three different species. However, the sequence of the C-terminal 9 amino acids appears to be significantly different. The authenticity of the rat cDNA was confirmed by the expression of an enzymatically active 15-PGDH in E. coli.

Amino Acid Sequence↗

The uvsF gene region in Aspergillus nidulans codes for a protein with homology to DNA replication factor C.

The UV-sensitive mutant uvsF201 of Aspergillus nidulans shows increased spontaneous and UV-induced mutation and generally resembles mutants defective in nucleotide excision repair (NER). Fully-complementing uvsF clones were isolated from cosmid and cDNA libraries for sequencing. The uvsF gene is approximately 3.75 kb long and codes for a predicted polypeptide of 1092 amino acids (aa). Three small introns are clustered early in the coding region of the protein. A major part of the sequence shows homology to human, mouse and yeast RFC1 genes which code for the large subunit of the DNA replication factor C. The uvsF gene product may therefore function primarily in general DNA replication but in addition be required for the replication step of DNA repair. Extended sequencing of the uvsF gene region identified a second closely adjacent gene of unknown function which is divergently transcribed from a small (0.2 kb) intergenic promoter region.

Amino Acid Sequence↗

Isolation and characterization of chicken beta-catenin.

beta-catenin interacts with a number of proteins in different important biological processes, including cell adhesion through cadherins, actin organization through fascin, body axis determination through Wnt signaling, tumor suppression through APC, and transcriptional activation through LEF-1. To examine its function in chicken embryogenesis, we isolated the chicken homolog of beta-catenin from a chicken embryo cDNA library. The sequence is highly conserved at the amino acid level between chicken, mouse (99%), human (99%) and Xenopus (97%). In-situ hybridization and immunostaining showed that in the developing limb, it is specifically expressed in the apical ectodermal ridge, suggesting a role in epithelial-mesenchymal interactions.

Amino Acid Sequence↗

Xenopus crescent encoding a Frizzled-like domain is expressed in the Spemann organizer and pronephros.

The Spemann organizer can be subdivided into head- and trunk-inducing tissues along the anteroposterior axis (Mangold, 1933. Naturwiisenschaften 43, 761-766; Spemann, 1931. Wilhelm Roux Arch. Entwicklungsmech. Org. 123, 389-517). Recent studies have suggested that head formation is brought about by repression of both Wnt and BMP signalling (Glinka et al., 1998. Nature 391, 357-362; Glinka et al., 1997. Nature 389, 517-519). Several Wnt inhibitors secreted from the head organizer region have been identified in Xenopus, such as Cerberus (Bouwmeester et al., 1996. Nature 382, 595-601), Frzb-1 (Leyns et al., 1997. Cell 88, 747-756; Lin et al., 1997. Proc. Natl. Acad. Sci. USA 94, 11196-11200), and Dkk-1 (Glinka et al., 1998. Nature 391, 357-362), supporting this two-inhibitor model. To isolate genes expressed in the head organizer, we screened a prechordal plate cDNA library by sequencing and expression pattern, and isolated the Xenopus ortholog of chick crescent encoding a Frizzled-like domain that is related to Wnt-binding regions of the Frizzled-family proteins. Expression of Xenopus crescent was first detected in the Spemann organizer region at the early gastrula stage and later in prechordal plate cells lining the boundary of mesoderm and ectoderm layers and in the anterior endoderm. At tailbud stages, the expression in the endomesoderm region was diminished, while expression in the pronephros became detectable. In animal cap assays, crescent gene was synergistically upregulated by coexpression of Xlim1, Ldb1, and Siamois, but not by Activin treatment.

Amino Acid Sequence↗

Identification of novel antifungal nonapeptides through the screening of combinatorial peptide libraries based on a hexapeptide motif.

Four sets of mixture based nonapeptide libraries derived from an antifungal hexapeptide pharmacophore Arg-D-Trp-D-Phe-Ile-D-Phe-His-NH(2) (II) have been synthesized. The three C-terminal positions 7, 8 and 9 were subject to randomization using 19 genetically coded amino acids. They were then screened for their antifungal activity against Candida albicans and Cryptococcus neoformans in order to quantify inhibition at each step of the nonapeptide sublibrary deconvolution. The studies led to the identification of several novel nonapeptides with potent antifungal activity. Two of the nonapeptides exhibited approximately 17-fold increase in the activity in comparison to the lead hexapeptide motif His-D-Trp-D-Phe-Phe-D-Phe-Lys-NH(2) (I) against C. albicans.

Amino Acid Motifs↗

cDNA cloning and expression of a hormone-regulated heat shock protein (hsc 70) from the prothoracic gland of Manduca sexta.

The brain neuropeptide prothoracicotropic hormone (PTTH) stimulates a rapid increase in ecdysteroid hormone synthesis that is accompanied by general and specific increases in protein synthesis, including that of a 70 kDa cognate heat shock protein (hsc 70). To further understand the possible roles of hsc 70, hsc 70 cDNA clones were isolated from a tobacco hornworm (Manduca sexta) prothoracic gland cDNA library. All sequenced clones were highly homologous to the Drosophila hsc 70-4 isoform. Manduca hsc 70 mRNA levels during the last larval instar exhibited a peak at the onset of wandering and a peak that coincided with the major pre-metamorphic peak of ecdysteroid synthesis. Manipulations of the glands' hormonal milieu showed that hsc 70 mRNA levels respond to 20-hydroxyecdysone, dibutyryl cAMP, PTTH and the JH analogue hydroprene. The protein and mRNA data suggest that hsc 70 could be involved in a negative feedback loop regulating assembly of the ecdysone receptor complex.

Amino Acid Sequence↗

Gene expression changes in BVDV2-infected MDBK cells.

Bovine viral diarrhoea virus (BVDV) is a ubiquitous viral pathogen of cattle. The virus exists as one of two biotypes, cytopathic and non-cytopathic, based on the ability to induce cytopathic effect in cell culture. The non-cytopathic biotypes are able to establish non-apparent, persistent infections in both cell culture and in bovine foetuses of fewer than 150 days gestation. The mechanism by which viral tolerance is established is unknown. To examine the changes in gene expression that occur following infection of host cells with BVDV, serial analysis of gene expression (SAGE), a global gene expression technology was used. SAGE, a sequence-based technology, allows quantification of virtually every transcript in a cell type without prior sequence information. Transcript expression levels and identities are determined by DNA sequencing of libraries composed of 14 base DNA fragments (tags) derived from the 3' end of each cellular mRNA transcript. Comparison of data obtained from non-infected and BVDV2-infected cell libraries revealed a number of changes in gene expression. Many of these transcriptional changes could be placed into distinct biochemical pathways or functions. Both alpha and beta tubulins were downregulated, indicating possible dysfunction in cell division and other functions where microtubules play a major role. Expression of several genes encoding proteins involved in energy metabolism were downregulated, indicating possible decreased ATP synthesis. Genes encoding proteins involved in protein translation and post-translational modifications were generally upregulated. These data indicate that following infection with BVDV, changes in gene expression occur that are beneficial for virus replication while placing the cell at a metabolic disadvantage.

Adenosine Triphosphate↗

The nonribosomal code.

How genes are expressed and translated into proteins (using mRNA, codons and tRNAs as adaptor molecules) forms the basis of the 'genetic code'. Many peptides are synthesized nonribosomally, however, by large protein complexes that also serve as templates. Recent advances have shed light on what the nonribosomal code is and how it can be read.

Acylation↗