Search results for "Exon"
showing 10 items of 437 documents
Transcription of different exons 1 of the human neuronal nitric oxide synthase gene is dynamically regulated in a cell- and stimulus-specific manner.
2003
An extensive screening of the human neuronal nitric oxide synthase (nNOS) mRNAs in various human tissues and cell lines unraveled an extreme complexity in the transcription of this gene. Using 5'rapid amplification of cDNA ends (5'-RACE), ten different exons 1 (named 1a-1l) were identified. They were spliced in a cell-specific manner to a common exon 2, which bears the translational start site. Three first exons (1 d, 1g and 1f) were used predominantly for the transcription of the nNOS gene (146 out of 197 5'-RACE clones contained these exons). Exon 1 k was found alone, but in many instances was interposed between exons 1 b, 1d, 1g, 1 i or 1j and the common exon 2. In addition to the cell-s…
One gene, two transcripts: isolation of an alternative transcript encoding for the autoantigen La/SS-B from a cDNA library of a patient with primary …
1994
A cDNA library was prepared from peripheral blood lymphocytes of an autoimmune patient with primary Sjögrens' syndrome. The cDNA library was screened with the patients own autoimmune serum being monospecific for the nuclear autoantigen La/SS-B. Thereby an alternative type of La mRNA was identified that differed from the known La mRNA due to an exchange of the exon 1. Sequencing of the genomic region between the exons 1 and 2 showed that the alternative 5'-end is a part of the intron. In addition, the presence of an alternative promoter site, which exists within the intron downstream of the exon 1, became evident. In consequence, the alternative La mRNA is the result of a promoter switching …
Analysis of expression of the gene encoding for the nuclear autoantigen La/SS-B using reporter gene constructs.
1998
In earlier studies mRNA isoforms encoding for the nuclear autoantigen La were identified. In an alternative La mRNA form the exon 1 was replaced with the exon 1'. Moreover, exon 1' La mRNAs were found to start at different 5'-regions. In dependence on the 5'-start the exon 1' La mRNAs encoded for up to three open reading frames upstream of the La frame, which starts in the exon 2. The exon 1' was located in the intron about 70 nts downstream of the exon 1. The exon 1' La mRNA was proposed to be the result of a promoter switch in combination with an alternative splicing mechanism. The commonly used technique to study the expression of a eucaryotic gene is to fuse a reportergene immediately d…
The evolution of splicing: transcriptome complexity and transcript distances implemented in TranD
2021
AbstractAlternative splicing contributes to organismal complexity. Comparing transcripts between and within species is an important first step toward understanding questions about how evolution of transcript structure changes between species and contributes to sub-functionalization. These questions are confounded with issues of data quality and availability. The recent explosion of affordable long read sequencing of mRNA has considerably widened the ability to study transcriptional variation in non-model species. In this work, we develop a computational framework that uses nucleotide resolution distance metrics to compare transcript models for structural phenotypes: total transcript length,…
Generation of GAL4-responsive muscleblind constructs
2002
The muscleblind (mbl) gene encodes protein isoforms Mbl A to Mbl D, which arise by alternative splicing from a common primary transcript. Mbl A, B, and C contain two Zn-finger domains of the type Cys3His, while Mbl D contains only one complete Zn finger. Loss of function mutations in the gene reveal that mbl is involved in both terminal photoreceptor and muscle differentiation in Drosophila. During retina development mbl is essential for rhabdomere differentiation in photoreceptor neuron. Clones homozygous null for mbl completely lack these lightharvesting structures (Begemann et al., 1997). Similarly, the terminal differentiation of the larval body wall muscles is compromised in mbl mutant…
Insensitivity to Aβ42-lowering Nonsteroidal Anti-inflammatory Drugs and γ-Secretase Inhibitors Is Common among Aggressive Presenilin-1 Mutations
2007
Abeta42-lowering nonsteroidal anti-inflammatory drugs (NSAIDs) constitute the founding members of a new class of gamma-secretase modulators that avoid side effects of pan-gamma-secretase inhibitors on NOTCH processing and function, holding promise as potential disease-modifying agents for Alzheimer disease (AD). These modulators are active in cell-free gamma-secretase assays indicating that they directly target the gamma-secretase complex. Additional support for this hypothesis was provided by the observation that certain mutations in presenilin-1 (PS1) associated with early-onset familial AD (FAD) change the cellular drug response to Abeta42-lowering NSAIDs. Of particular interest is the P…
Aberrant splicing of the Drosophila melanogaster phenylalanine hydroxylase pre-mRNA caused by the insertion of a B104/roo transposable element in the…
1999
Abstract We report the insertion of the transposable element B104 in the Phenylalanine hydroxylase gene of the Drosophila mutant Henna-recessive 3 . Its presence alters the Phenylalanine hydroxylase splicing pattern, producing at least two aberrant mRNAs which contain part of the B104 sequence interrupting the coding region. This aberrant splicing is provoked by the use of a cryptic donor site encoded by the B104 3′ long terminal repeat in combination with either the gene intron 3 acceptor site or a novel acceptor site generated by the target duplication caused by transposition. One of them, referred as mRNA type 1, encodes a truncated protein that could be predictably non-functional. In mR…
P sequences ofDrosophilla Subobscuralack exon 3 and may encode a 66 kd repressor-like protein
1991
Abstract Several P homologous sequences have been cloned and sequenced from Drosophila subobscura. These sequences are located at the 85DE region of the O chromosome and at least three of them are organized in tandem. We have identified four copies which exhibit strong similarity between them. All of the isolated elements are truncated at the 5' and 3' ends. They have lost the inverted terminal repeats and exon 3, but maintain exons 0, 1 and 2. They are transcribed producing a polyadenylated RNA. The structure of these transcripts suggests that they are able to encode a 66 kd repressor-like protein, but not a functional transposase. We ask about the biological role of a potential repressor …
Common genomic structure for the Lepidoptera cadherin-like genes.
2005
A cadherin-like protein present in the midgut epithelial cells of Lepidoptera is associated with insect resistance to Bacillus thuringiensis Cry toxins. We describe for the first time the genes that encode the cadherin-like proteins in Ostrinia nubilalis, Helicoverpa armigera, and Bombyx mori, and analyze their organization. These genes encompass 19.6 kb, 20.0 kb, and 41.8 kb of genomic DNA, respectively, and despite the size heterogeneity, they are all composed of 35 exons that are linked by 34 introns. In contrast to the high variability noted for the sizes of the introns, the sizes of the coding exons were almost completely preserved among the three species, because the intronic sequence…
Analysis of the p53 and MDM-2 gene in acute myeloid leukemia
1996
The MDM-2 (murine double minute 2) gene codes for a cellular protein that can bind to the p53 tumor suppressor gene product, thereby functioning as a negative regulator of p53. In order to define the role of the MDM-2 gene in the pathogenesis of human acute myeloid leukemia, the expression and the sequence of the MDM-2 gene were examined in samples of bone marrow and/or peripheral mononuclear cells of 38 patients by using immunostaining, polymerase chain reaction (PCR), single strand conformation polymorphism, and sequencing. Immunohistochemical staining detected a weak accumulation of the MDM-2 protein in AML patients of FAB classification M4 and M5. RT-PCR analysis revealed a heterogeneou…