Search results for " RNA"

Alternatively spliced transcripts of the thymus-specific protease PRSS16 are differentially expressed in human thymus.

2004

The putative serine protease PRSS16 is abundantly expressed in the thymic cortex and the gene is encoded within the HLA I complex. Although its function is not yet defined, the very restricted expression points to a role in T-cell development in the thymus. In this study, we show that the PRSS16 mRNA is alternatively spliced to generate at least five transcripts. Apart from the full-length sequence, we found two other isoforms with all putative active site residues of the serine protease, suggesting that those variants may also be functional. Semi-quantitative analysis of the splice variants in different tissue samples revealed a strong correlation between the specific formation of alternat…

Quantitative RT-PCR measurement of human cytochrome P-450s: application to drug induction studies.

2000

A quantitative RT-PCR assay has been developed that is able to measure the mRNA content of the major human CYPs (1A1, 1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4, and 3A5). The technique is highly specific, reproducible, rapid, and sensitive enough to quantitate low and high abundant mRNAs. The PCR primers were selected to specifically match each CYP mRNA, to have a very close annealing temperature, and to render PCR products of similar sizes. The PCR conditions were designed to allow the simultaneous measurement of the various human liver CYPs in a single run. To achieve precise and reproducible quantitation of each cytochrome mRNA, a external standard (luciferase mRNA) is added to the probes …

Different La/SS-B mRNA isoforms are expressed in salivary gland tissue of patients with primary Sjogren's syndrome

1996

Recently we isolated a La/SS-B mRNA isoform from a cDNA library made from peripheral blood lymphocytes of a patient with primary Sjögren's Syndrome. In the La/SS-B mRNA isoform the exon 1 was replaced. The alternative exon was termed exon 1'. Genomic analysis showed that the exon 1' La mRNA was the result of a promoter-switch in combination with alternative splicing. Due to the unusual structure of the exon 1' La/SS-B mRNA, the function and the behaviour under physiological and pathophysiological conditions in tissue of patients with primary Sjögren's syndrome or Systemic Lupus Erythematosus remained obscure. Therefore assays were established allowing a qualitative and quantitative estimati…

An altered intracellular distribution of the autoantigen La/SS-B when translated from a La mRNA isoform.

1997

Abstract Transcription of the gene encoding for the nuclear autoantigen La resulted in La mRNA isoforms. A promoter switching combined with an alternative splicing pathway replaced exon 1 with exon 1′. Similar to mRNAs encoding for ribosomal proteins, exon 1′ started with a pyrimidine-rich 5′-terminus. Moreover, exon 1′ contained 5′-GC-rich regions and an oligo(U)-tail of 23 uridine residues. Exon 1′ encoded for three open reading frames upstream of the La protein reading frame. In spite of this unusual structure, exon 1′ La mRNAs were translated not only in vitro but also in transiently transfected cells. The translational efficiency of exon 1′ La mRNA was about 14% of exon 1 La mRNA using…

Semi-automatic quantitative RT-PCR to measure CYP induction by drugs in human hepatocytes

2003

An assay has been developed for the quantitative measurement of CYP mRNA content of the major human isoforms (1A1, 1A2, 2A6, 2B6, 2C9, 2C19, 2D6, 2E1, 3A4 and 3A5) in human hepatocytes. The method is based on the conversion of mRNAs into their corresponding cDNAs, followed by PCR amplification using appropriate primers. Making use of appropriate internal and external standards it is possible to estimate changes in CYP mRNA content of hepatocytes. The technique has been standardised to run semi-automatically. This procedure can be used to assess the CYP induction potential of new pharmaceuticals at a pre-clinical stage of development. To this aim, human hepatocytes obtained from functional l…

2013

Clusterin, also known as apolipoprotein J, is expressed from a variety of tissues and implicated in pathological disorders such as neurodegenerative diseases, ischemia and cancer. In contrast to secretory clusterin (sCLU), which acts as an extracellular chaperone, the synthesis, subcellular localization and function(s) of intracellular CLU isoforms is currently a matter of intense discussion. By investigating human CLU mRNAs we here unravel mechanisms leading to the synthesis of distinct CLU protein isoforms and analyze their subcellular localization and their impact on apoptosis and on NF-κB-activity. Quantitative PCR-analyses revealed the expression of four different stress-inducible CLU …

Dendritic localization of mammalian neuralized mRNA encoding a protein with transcription repression activities.

2002

Drosophila neurogenic gene neuralized (neu) is required for the maintenance of neuroblast cell fate and differentiation. In the present study we have characterized a mouse and a rat homologue of Drosophila neu. Mammalian neu1 encodes several C-terminal RING zinc finger proteins with one or two neuralized homology repeat (NHR) domains. Mammalian neu1 mRNAs are predominantly expressed in the nervous system and in the skeletal muscle with the highest levels in the adult. In the nervous system neu1 mRNAs are expressed in neurons and dendritically localized in several brain regions, suggesting a role of neu1 in the regulation of synaptic function. Mammalian neu1 isoforms exhibit transcription re…

Similar Regulation of Human Inducible Nitric-oxide Synthase Expression by Different Isoforms of the RNA-binding Protein AUF1

2008

The ARE/poly-(U) binding factor 1 (AUF1), a protein family consisting of four isoforms, is believed to mediate mRNA degradation by binding to AU-rich elements (ARE). However, evidence exists that individual AUF1 isoforms may stabilize ARE-containing mRNAs. The 3'-untranslated region of the human inducible nitric-oxide synthase (iNOS) contains five AREs, which promote RNA degradation. We have recently shown that the RNA-binding protein KSRP is critically involved in the decay of the iNOS mRNA. In this study we examined the effects of the individual AUF1 isoforms on iNOS expression. Overexpression of each AUF1 isoform reduces iNOS expression on mRNA and protein levels to the same extent by mo…

Potential Functional Significance of Brain-Type and Muscle-Type Nitric Oxide Synthase I Expressed in Adventitia and Media of Rat Aorta

1999

Abstract —Skeletal muscle and myocardium express μNOS I, an elongated splice variant of neuronal-type nitric oxide (NO) synthase (NOS I), and NOS III, endothelial-type NO synthase, respectively. This study was designed to elucidate whether vascular smooth muscle also contains a constitutively expressed NO synthase isoform. In the rat, μNOS I contains an insert of 102 nucleotides after nucleotide 2865 of the cDNA, yielding a protein of 164 kd. Reverse transcription-polymerase chain reaction with primers flanking this insert and with insert-specific primers indicated that endothelium-denuded rat aorta expresses both brain-type NOS I and μNOS I. RNase protection analyses with an antisense RNA…

NGF and TGF-beta mRNA expression during pregnancy in a rat corneal wound healing model.

2003

Background Growth factors seem to play a major role in corneal wound healing and TGF-beta seems to be associated with abnormal healing after corneal surgical procedures. Few studies have analysed the role of NGF and TGF-beta on corneal wound healing during pregnancy. The aim of the present study was to create an animal model to evaluate the expression of NGF and TGF-betas during corneal wound healing in two groups: control and pregnant rats. Methods Corneal mRNA for NGF and the three isoforms of TGF-beta were analysed by RT-PCR, in a time-course experiment on different days after epithelial wounding (2, 7, 14 days) in pregnant and control groups Results The results show high corneal mRNA ex…