Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The isolation and characterization of the rat genomic clone encoding the cholesterogenic enzyme farnesyl diphosphate (FPP) synthase is reported. The gene is localized on a 15-kilobase (kb) genomic fragment, spans approximately 12 kb and contains eight exons. Sequences containing from 3.9 kb to 132 base pairs (bp) of the putative promoter were joined to the coding region of the bacterial reporter gene chloramphenicol acetyltransferase (CAT). The CAT activities or CAT mRNA levels of the hybrid genes were determined following either transient transfections into human hepatoma HepG2 cells or stable transfections into Chinese hamster ovary cells. The transient transfections identified a 319-bp fragment that was required for a 4-fold induction in the absence of sterols. Sequence analysis of this region showed it contained five potential copies of the sterol regulatory element (SRE-1) (Smith, J.R., Osborne, T.F., Brown, M.S., Goldstein, J.L., and Gil, G. (1988) J. Biol. Chem. 263, 18480-18487) previously identified in the promoters of the 3-hydroxy-3-methyl-coenzyme A (HMG-CoA) reductase, HMG-CoA synthase, and low density lipoprotein receptor genes. Further mutational and deletion analysis of the FPP synthase promoter-CAT constructs followed by stable transfection and primer extension of the CAT mRNA levels indicated that these potential SRE-1 regulatory elements were not involved in the sterol-mediated transcriptional regulation of the gene. Our analyses have identified a 115-bp region that is required for the transcriptional induction of FPP synthase in the absence of sterols. These results suggest that the FPP synthase gene may be regulated at the transcriptional level by a different mechanism than other sterol regulated genes.
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PMID:Molecular cloning and promoter analysis of the rat liver farnesyl diphosphate synthase gene. 132 Nov 49

A cluster of four tRNACys-encoding genes with the anticodon GCA was found on a murine genomic clone containing an 18-kb DNA insert. Three of the four genes encode the identical tRNA, whereas the fourth gene has an altered nucleotide (nt) sequence. Two of the genes within a 2-kb PvuII fragment have the same polarity and are separated by only 921 bp. These two tRNAs have a different primary sequence. The changes in the nt sequences occur within three stems of the tRNA cloverleaf structure and weaken the strength of the H-bonds within the stems. All four genes (designated i-iv) have the 3' structural element that has been proposed as the transcription termination signal [Bogenhagen and Brown, Cell 24 (1981) 261-270]. The remainder of the flanking regions of the three identical tRNAs are very similar to each other, whereas the flanking regions of the fourth tRNA are distinctly different.
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PMID:Isolation of a mouse genomic clone containing four tRNACys-encoding genes. 201 65

A full-length genomic clone for human tyrosine hydroxylase (L-tyrosine, tetrahydropteridine:oxygen oxidoreductase, EC 1.14.16.2) has been isolated. A human brain genomic library constructed in EMBL3 was screened by using a rat cDNA for tyrosine hydroxylase as a probe [Brown, E. R., Coker, G. T., III, & O'Malley, K. L. (1987) Biochemistry 26, 5208-5212]. Out of one million recombinant phage, one clone was identified that hybridized to both 5' and 3' rat cDNA probes. Restriction endonuclease mapping. Southern blotting, and sequence analysis revealed that, like its rodent counterpart, the human gene is single copy, contains 13 primary exons, and spans approximately 8 kilobases (kb). In contrast to the rat gene, human tyrosine hydroxylase undergoes alternative RNA processing within intron 1, generating at least three distinct mRNAs. A comparison of the human tyrosine hydroxylase and phenylalanine hydroxylase [DiLella, A. G., Kwok, S. C. M., Ledley, F. D., Marvit, J., & Woo, S. L. C. (1986) Biochemistry 25, 743-749] genes indicates that although both probably evolved from a common ancestral gene, major changes in the size of introns have occurred since their divergence.
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PMID:Isolation and characterization of the human tyrosine hydroxylase gene: identification of 5' alternative splice sites responsible for multiple mRNAs. 289 28

To identify genes specifically or predominantly expressed in the stigmas/styles and to establish their possible function in the reproductive process of plants, a tobacco stigma/style cDNA library was constructed and differentially screened, resulting in the isolation of several cDNA clones. The molecular characterization of one of these clones is described here. After sequencing the cDNA and the isolated genomic clone, it was determined that the corresponding gene encodes a protein containing an ATP-binding cassette, characteristic of ABC transporters. This gene, designated as NtWBC1 (Nicotiana tabacum ABC transporter of the White-Brown Complex subfamily), encodes a protein that contains the typical structure of the 'half-transporters' of the White subfamily. To establish the spatial expression pattern of the NtWBC1 gene, northern blot and real-time RT-PCR analyses with total RNA from roots, stems, leaves, sepals, petals, stamens, stigmas/styles, ovaries, and seeds were performed. The result revealed a transcript of 2.5 kb present at high levels in stigmas and styles and a smaller transcript (2.3 kb) present at a lower level in stamens. NtWBC1 expression is developmentally regulated in stigmas/styles, with mRNA accumulation increasing toward anthesis. In situ hybridization experiments demonstrated that NtWBC1 is expressed in the stigmatic secretory zone and in anthers, at the stomium region and at the vascular bundle. NtWBC1 is the first ABC transporter gene with specific expression in plant reproductive organs to be identified and its expression pattern suggests important role(s) in the reproductive process.
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PMID:NtWBC1, an ABC transporter gene specifically expressed in tobacco reproductive organs. 1525 65