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At least 163 records · Page 9Linked to original sources
PubMed1993

Structural characterization and expression analysis of the Neurospora conidiation gene con-6.

The gene con-6 of Neurospora crassa is expressed during the formation of asexual spores (conidia), but it is not expressed in mycelium. con-6 mRNA appears upon induction of conidiation and reaches high levels at the late stages of conidiation, and in mature conidia. The CON6 polypeptide and a CON6-beta-Gal fusion protein were present at high levels only in free conidia. Shortly after spore germination con-6 mRNA disappears and the CON6 polypeptide is degraded. CON6 is a small, hydrophilic polypeptide containing a repeat sequence; it not homologous to any known protein but has features resembling the late embryogenesis abundant proteins of maize. Inactivation of con-6 by the repeat-induced point mutation process had no demonstrable effect on formation or germination of conidia. Upstream sequence comparisons for con-6 and other con genes identified a common potential regulatory sequence, designated CRS-B. DNA mobility shift analyses with cell extracts identified a factor that bound to synthetic DNA fragments containing this sequence. This binding factor was present in mycelium but not in conidiating cultures. Experiments with independent integrated con-6'-'lacZ translational fusions revealed substantial variability of expression among transformants carrying identical fusion constructs: This variability may be due to the differential methylation of transformant DNA noted by others.

Amino Acid Sequence↗
PubMed1998

Sequence and expression analysis of a Drosophila gene product related to the tre oncogene.

We report the sequence and expression of a Drosophila cDNA that shows similarity to a portion of the tre oncogene. The deduced encoded protein, DRN-TRE, contains residues that are highly conserved across a wide phylogenetic spectrum. The temporal and spatial transcription pattern of DRN-TRE suggest that it functions in a broad range of tissues.

Amino Acid Sequence↗
PubMed1999

Expression analysis of six paralogous human hyaluronidase genes clustered on chromosomes 3p21 and 7q31.

Two new members of a family of putative hyaluronidase genes involved in glycosaminoglycan catabolism have been identified and mapped by FISH and YAC library screening to chromosome 7q31.3. One of these (HYALP1) is an expressed pseudogene with mutations in the genomic DNA and cDNA. The six members of the hyaluronidase family are grouped into two tightly linked triplets on human chromosomes 3p21.3 (HYAL1, HYAL2, and HYAL3) and 7q31.3 (HYAL4, SPAM1 (PH-20), and HYALP1). This arrangement could arise by an ancient cluster formation, followed by a more recent cluster block-duplication. All of the hyaluronidase genes have unique tissue-specific expression patterns as determined by Northern blot analysis of 23 human tissues. HYAL1, HYAL2, and HYALP1 are widely expressed, but HYAL3 is differentially expressed in bone marrow and testis, while HYAL4 is differentially expressed in placenta and skeletal muscle. SPAM1 (PH-20) was detectable only in testis by Northern blot as previously reported, but was detectable in fetal and placental cDNA libraries by PCR, suggesting a possible role for this gene during embryonic development.

Amino Acid Sequence↗
PubMed1995

Cloning and developmental expression analysis of the murine c-mer tyrosine kinase.

We have cloned the putative mouse homologue of the human c-mer receptor tyrosine kinase proto-oncogene. Comparison of the mouse and human c-mer amino acid sequences reveals an overall identity of 88%. Similar to the human, the extracellular region of the murine c-mer protein possesses two amino terminal immunoglobulin-like domains and two membrane proximal fibronectin type III domains, which places it in the Axl family of tyrosine kinases. Our analysis of the Axl family identifies eight different regions of amino acid consensus that have residues characteristic of this and no other tyrosine kinase family; six of the eight are within tyrosine kinase subdomains. The homology within the Axl family is highest between c-mer and c-eyk, the chicken proto-oncogene of the tumor virus gene product v-eyk. Northern analysis of adult tissues suggests that the mouse c-mer, although expressed in many tissues, has an expression pattern unique among Axl family members. In normal adult hematopoietic cells c-mer seems to be expressed predominantly if not exclusively in the monocytic lineage. Mouse c-mer is expressed during most, if not all, stages of embryological development beginning in the morula and blastocyst and progressing through the yolk sac and fetal liver stages. This early and consistent expression of c-mer was confirmed during in vitro differentiation of embryonic stem cells. The embryonic expression profile of c-mer suggests that this tyrosine kinase may play an important function in the developing mouse.

Amino Acid Sequence↗
PubMed1998

Protein tyrosine phosphatase gene expression analysis in Swiss 3T3 fibroblasts.

The aim of this study was to identify protein tyrosine phosphatases (PTPs) expressed in Swiss 3T3 fibroblasts and to examine their expression levels as well as to characterize quantitative aspects of RT-PCR based on degenerate deoxyoligonucleotides. By using an RT-PCR assay based on degenerate deoxyoligonucleotide primers, expression of mRNAs for two cytoplasmic- and six transmembrane-type PTPs in Swiss 3T3 cells was detected. The sequences of two of them are new. Among nine analyzed PTPs expressed to widely varied extends, only three have mRNA levels high enough to be seen on Northern blots with 10 microg of total RNA per lane. The frequencies with which the examined PTPs are represented among the PCR amplification products, correlate stronger with the primer fidelity, defined as the number of mismatches between the primer- and the cDNA target-sequences, rather than with the PTP expression levels. In conclusion, an RT-PCR assay based on degenerate primers can be successfully used to sample the expressed PTPs and to identify new members of this gene family. However, reliable quantification of their mRNA levels can only be achieved using the classical approaches, like Northern, RNase protection assay or nondegenerate quantitative RT-PCR.

3T3 Cells↗
PubMed1991

An immune response defect due to low levels of class II cell surface expression. Analysis of antigen presentation and positive selection.

The effects of quantitative differences in class II cell surface expression have been difficult to address in intact animals. This study uses several lines of H-2s/s mice carrying an A beta k transgene that differ significantly in terms of class II cell surface expression. Due to inefficient chain pairing, mice carrying 60 to 65 copies of this transgene express only low levels of A alpha s/A beta k on the cell surface, and cell surface expression of the endogenous A alpha s/A beta s complex (and total Ia) is severely reduced (to 7-15% control levels). The significant decrease in class II cell surface expression in the thymic cortex of these mice did not affect the frequency of peripheral T cells expressing at least 10 distinct TCR V beta chains. However, T cell proliferative responses to the A alpha s/A beta s-restricted peptide MBP 89-101 were abrogated in high copy number A beta k mice. Experiments using bone marrow chimeras demonstrated that both inefficient Ag presentation and failure to positively select appropriate T cells contributed to this lack of response. Inefficient Ag presentation was clearly the dominant defect, and the density of class II cell surface expression required for positive selection appeared to be quite low.

Animals↗
PubMed1995

Cloning and expression analysis of a cytochrome P-450(11 beta) cDNA in sheep.

A full length ovine steroid 11 beta-hydroxylase (cytochrome P-450(11 beta)) cDNA clone from a sheep adrenal cortex cDNA library was isolated. Sequence analysis indicates that this cDNA clone resembles bovine P-450(11 beta) cDNA (95% nucleotide sequence homology) more closely than rat P-450(11 beta) cDNA (69% nucleotide sequence homology). Although the levels of nucleotide sequence homology of this cDNA clone to the rat P-450(11 beta) cDNA and the rat P-450aldo cDNA are similar, the putative amino acid sequence shows a closer resemblance to rat P-450aldo protein. Northern blot analysis shows that there are three sizes of transcript and they are expressed throughout the adrenal cortex.

Adrenal Cortex↗
PubMed1999

cDNA cloning and expression analysis of mouse zf9, a Krüppel-like transcription factor gene that is induced by adipogenic hormonal stimulation in 3T3-L1 cells.

Using a differential hybridization method, we have cloned a zinc finger transcription factor gene whose expression was enhanced by adipogenic hormones in preadipocyte 3T3-L1 cells. Cloning of this gene revealed that it encodes a mouse homologue of rat Zf9 and human CPBP/GBF, previously identified as a wound-induced transcription factor and GC-rich binding protein, respectively. The mRNA for this clone consisted of 0.9 kb coding region and 3.2 kb long 3' untranslated region. Northern blot analysis revealed that it was ubiquitously expressed, among adult tissues, in which abundant expression was observed in lung, ovary and thymus. The transcript was transiently induced by different stimuli such as serum, cAMP and 12-O-tetradecanoylphorbol 13-acetate. Nuclear run-on and RNA synthesis inhibitor chase experiments indicated that the transient induction of the mRNA was regulated both at transcriptional and post-transcriptional levels.

3T3 Cells↗
PubMed1997

Expression analysis and chromosomal assignment of the human SFRS5/SRp40 gene.

Alternative splicing plays a major role in the regulation of gene expression. SFRS5/SRp40 is a member of the serine/arginine (SR) protein family of regulators of alternative pre-mRNA splicing. We cloned the human SFRS5 cDNA and observed two major SFRS5 transcripts, an approximately 1.8-kb short form and an approximately 3.3-kb long form, in both human and rat tissues. Both transcripts were detected in all human tissues examined, but there were notable tissue-specific differences in their relative abundance, the short form being most abundant in retina. Affinity-purified SFRS5 antisera recognized a single 40-kDa polypeptide in human and mouse retinal lysates. The abundant retinal expression of SFRS5 was not restricted to any specific cell type, since immunofluorescent labeling of human retinal sections identified the SFRS5 protein in nuclei of all three nuclear layers of the retina. The human SFRS5 gene was localized to human chromosome 14q24 by fluorescence in situ hybridization and PCR analysis of a human/hamster somatic cell hybrid panel.

Alternative Splicing↗
PubMed1986

Isolation, physical characterization and expression analysis of the Saccharomyces cerevisiae positive regulatory gene PHO4.

The Saccharomyces cerevisiae PHO4 gene, which positively controls the expression of phosphatase genes, has been isolated by complementation of a pho4 mutation. The isolated DNA directed integration at the chromosomal PHO4 locus. The nucleotide sequence of PHO4 has a coding region of 930 nucleotides, flanked by sequences with typical transcription initiation and termination signals. The 5' region has characteristics of low-expression promoters and carries several uncommon elements, whose significance is not known. The predicted primary structure of the PHO4 protein, of 309 residues, does not show sequence elements typical of DNA-binding proteins. The transcription of PHO4 is independent of inorganic phosphate. Like other regulatory genes, PHO4 is transcribed at a very low level and the translation of its message uses preferentially several codons which are not employed for highly expressed genes.

Amino Acid Sequence↗
PubMed1993

Expression analysis of cloned chromosomal segments of Escherichia coli.

The novel transcription system of bacteriophage T7 was used to express Escherichia coli genes preferentially with a new low-copy-number plasmid vector, pFN476, to minimize toxic gene effects. Selected E. coli chromosomal fragments from an ordered genomic library (Y. Kohara, K. Ikiyama, and K. Isono, Cell 50:495-508, 1987) were recloned into this vector, and their genes were preferentially expressed in vivo utilizing its T7 promoter. The protein products were analyzed by two-dimensional gel electrophoresis. By using DNA sequence information, the gel migration was predicted for the protein products of open reading frames from these segments, and this information was used to identify gene products visualized as spots on two-dimensional gels. Even in the absence of DNA sequence information, this approach offers the opportunity to identify all gene products of E. coli and map their genes to within 10 kb on the E. coli genome; with sequence information, this approach can produce a definitive expression map of the E. coli genome.

Bacterial Proteins↗
PubMed2000

Complete sequencing and mRNA expression analysis of the MEN-I gene in adrenal myelolipoma.

The molecular pathogenesis of adrenal myelolipoma is unclear. Endocrine activity of these tumors and association with other endocrine tumors have stimulated the hypothesis that it may belong to the group of sporadic tumors caused by defects of the gene responsible for multiple endocrine neoplasia type I (MEN-I). DNA of blood and tumoral sections from two patients with adrenal myelolipoma were analyzed by examination of variable number of tandem repeats (VNTR) loci PYGM, D11S987, D11S480, and D11S449 on chromosome 11q13 and by complete direct DNA sequencing of all coding exons and splice junctions of the MEN-I gene. Menin expression was examined by RT-PCR. RT-PCR did not detect menin expression in one adrenal myelolipoma. No loss of heterozygozity on chromosome 11q13 was identified. Intragenic heterozygozity was retained in codon 418 of the menin gene in both patients. No mutation was identified in the coding exons of the menin gene. Complete DNA sequencing yielded no hint that defects of the MEN-I gene are responsible for the formation of adrenal myelolipomas. Adrenal myelolipomas do not share the loss of heterozygozity on chromosome 11q13 observed in some benign adenomatous and many malignant adrenocortical tumors.

Adrenal Gland Neoplasms↗
PubMed1999

Expression analysis of glycogen synthase kinase-3 in human tissues.

Human glycogen synthase kinase-3 (GSK-3) is a multisubstrate, proline-directed kinase that phosphorylates tau, beta-amyloid and neurofilaments. In this study, the expression levels of the two GSK-3 isoforms, alpha and beta, RNA and proteins in different human tissues were examined. Northern analysis demonstrated that GSK-3alpha is encoded by a 2.6-kb mRNA and GSK-3beta by 8.3- and 2.8-kb mRNAs. The two GSK-3beta mRNA species were variably expressed in different tissues. Northern and quantitative polymerase chain reaction demonstrated that both GSK-3alpha and GSK-3beta mRNA were prominently expressed in testis, thymus, prostate and ovary but were low in adult lung and kidney. Western blot analysis showed that the 51-kDa GSK-3alpha protein was highly expressed in lung, ovary, kidney and testis, whereas the 46-kDa GSK-3beta protein was highly expressed in lung, kidney and brain. The differential expression of GSK-3alpha and GSK-3beta mRNA and proteins and the lack of relationship between transcription and translation in some tissues indicate that GSK-3alpha and GSK-3beta are subject to different means of regulation.

Adult↗
PubMed1998

Sequence of murine CDC10 cDNA, gene organization and expression analysis.

The sequence of the 2391 bp murine CDC10 cDNA is reported. The gene transcription unit, composed of 13 exons, encodes a potential 417/446 amino acid GTP-binding protein, highly similar to human CDC10. The ubiquitous expression of the gene, as judged by Northern analysis, is consistent with its putative promoter structure.

Amino Acid Sequence↗
PubMed2000

Human KLRF1, a novel member of the killer cell lectin-like receptor gene family: molecular characterization, genomic structure, physical mapping to the NK gene complex and expression analysis.

The human NK gene complex localized on chromosome 12p12.3 - p13.2 codes for several lectin-like receptor genes expressed by NK cells as well as by other hematopoietic cells. In this study, by using the expressed sequence tag database we identified a novel receptor gene, designated as killer cell lectin-like receptor, subfamily F, member 1 (KLRF1), encoding a putative type II transmembrane glycoprotein. The KLRF1 gene has been localized on the high-resolution physical map of chromosome 12p. The genomic structure of the KLRF1 gene and the existence of one spliced variant are also described. KLRF1 was expressed at the mRNA level in peripheral blood leukocytes, activated NK cells, monocytes and NK and myeloid cell lines. The presence of two immunoreceptor tyrosine-based inhibitory-like motifs within the cytoplasmic tail of KLRF1 suggests an inhibitory role in NK cell and monocyte activity.

Amino Acid Sequence↗
PubMed1998

Molecular cloning, functional characterization and mRNA expression analysis of the murine chemokine receptor CCR6 and its specific ligand MIP-3alpha.

We have cloned the murine CCR6 receptor and its ligand, the beta-chemokine mMIP-3alpha. Calcium mobilization assays performed with mCCR6 transfectants showed significant responses upon addition of mMIP-3alpha. Murine MIP-3alpha RNA is expressed in thymus, small intestine and colon, whereas mCCR6 RNA is expressed in spleen and lymph nodes. RT-PCR analysis of FACS-sorted lymphoid and antigen presenting cell subsets showed mCCR6 expression mainly in B cells, CD8- splenic dendritic cells and CD4+ T cells. The cloning and functional characterization of the mCCR6 and mMIP-3alpha will allow the study of the role of these proteins in mouse models of inflammation and immunity.

Amino Acid Sequence↗
PubMed2000

Characterization of the potato MADS-box gene STMADS16 and expression analysis in tobacco transgenic plants.

A new MADS-box gene, STMADS16, has been cloned in Solanum tuberosum L. that is expressed in all vegetative tissues of the plant, mainly in the stem, but not in flower organs. STMADS16 expression is established early during vegetative development and is not regulated by light. Sequence similarity besides the spatial and temporal expression patterns allow to define a novel MADS-box subfamily comprising STMADS16 and the gene STMADS11. Expression of the STMADS16 sense cDNA under the control of the 35S cauliflower mosaic virus promoter modifies the inflorescence structure by increasing both internode length and flower proliferation of the inflorescence meristems, and confers vegetative features to the flower. Moreover, STMADS16 ectopic expression overcomes the increase in flowering time and node number produced under short-day photoperiod, while the flowering time is not affected in long-day conditions. These results are discussed in terms of a possible role for STMADS16 in promoting vegetative development.

Amino Acid Sequence↗