Search results for "isoforms"
showing 10 items of 185 documents
Developmental expression of two Haliotis asinina hemocyanin isoforms
2005
Hemocyanins are large copper-containing respiratory proteins that play a role in oxygen transport in many molluscs. In some species only one hemocyanin isoform is present while in others two are expressed. The physiological relevance of these isoforms is unclear and the developmental and tissue-specific expression of hemocyanin genes is largely unknown. Here we show that two hemocyanin genes in the gastropod Haliotis asinina, which encode H. asinina hemocyanin (HaH1) and HaH2 isoforms, are developmentally expressed. These genes initially are expressed in a small number of mesenchyme cells at trochophore and pre-torsional veliger stages, with HaH1 expression slightly preceding HaH2. These ce…
Muscleblind isoforms are functionally distinct and regulate α-actinin splicing
2007
Drosophila Muscleblind (Mbl) proteins control terminal muscle and neural differentiation, but their molecular function has not been experimentally addressed. Such an analysis is relevant as the human Muscleblind-like homologs (MBNL1-3) are implicated in the pathogenesis of the inherited muscular developmental and degenerative disease myotonic dystrophy. The Drosophila muscleblind gene expresses four protein coding splice forms (mblA to mblD) that are differentially expressed during the Drosophila life cycle, and which vary markedly in their ability to rescue the embryonic lethal phenotype of muscleblind mutant flies. Analysis of muscleblind mutant embryos reveals misregulated alternative sp…
ΔNp73β is oncogenic in hepatocellular carcinoma by blocking apoptosis signaling via death receptors and mitochondria
2010
p73 belongs to the p53 family of transcription factors known to regulate cell cycle and apoptosis. The Trp73 gene has two promoters that drive the expression of two major p73 isoform subfamilies: TA and ΔN. In general, TAp73 isoforms show proapoptotic activities, whereas members of the N-terminally truncated (ΔN) p73 subfamily that lack the transactivation domain show antiapoptotic functions. We found that upregulation of ΔNp73 in hepatocellular carcinoma (HCC) correlated with reduced survival. Here, we investigated the molecular mechanisms accounting for the oncogenic role of ΔNp73 in HCC.ΔNp73β can directly interfere with the transcriptional activation function of the TA (containing the t…
The “Janus” Role of C/EBPs Family Members in Cancer Progression
2020
CCAAT/enhancer-binding proteins (C/EBPs) constitute a family of transcription factors composed of six members that are critical for normal cellular differentiation in a variety of tissues. They promote the expression of genes through interaction with their promoters. Moreover, they have a key role in regulating cellular proliferation through interaction with cell cycle proteins. C/EBPs are considered to be tumor suppressor factors due to their ability to arrest cell growth (contributing to the terminal differentiation of several cell types) and for their role in cellular response to DNA damage, nutrient deprivation, hypoxia, and genotoxic agents. However, C/EBPs can elicit completely opposi…
Gene structure and hemocyanin isoform HtH2 from the mollusc Haliotis tuberculata indicate early and late intron hot spots.
2002
Abstract We have cloned and sequenced cDNAs coding for the complete primary structure of HtH2, the second hemocyanin isoform of the marine gastropod Haliotis tuberculata. The deduced protein sequence comprises 3399 amino acids, corresponding to a molecular mass of 392 kDa. It shares only 66% of structural identity with the previously analysed first isoform HtH1, and according to a molecular clock, the two isoforms of Haliotis hemocyanin separated ca. 320 million years ago. By genomic polymerase chain reaction and 5′ race, we have also sequenced the complete gene of HtH2 (18,598 bp), except of the 5′ region in front of the secreted protein. It encompasses 15 exons and 14 introns and shows se…
Expression pattern of the Brachyury and Tbx2 homologues from the sponge Suberites domuncula.
2005
Background information. T-box transcription factors are a large family of transcriptional regulators involved in many aspects of embryonic development. In a previous report, we described the isolation and genomic characterization of two T-box genes from the siliceous sponge Suberites domuncula: a Brachyury homologue, Sd-Bra, and a Tbx2 homologue, Sd-Tbx2. Elucidation of the genomic structure of Sd-Bra allowed us to demonstrate the existence of two different isoforms, resulting from alternative splicing. Moreover, we demonstrated that the shorter isoform exists in two different glycosylation states. Results. In the present study, we demonstrate a differential subcellular localization of the …
The diversity of GABAA receptors. Pharmacological and electrophysiological properties of GABAA channel subtypes.
1998
The amino acid gamma-aminobutyric-acid (GABA) prevails in the CNS as an inhibitory neurotransmitter that mediates most of its effects through fast GABA-gated Cl(-)-channels (GABAAR). Molecular biology uncovered the complex subunit architecture of this receptor channel, in which a pentameric assembly derived from five of at least 17 mammalian subunits, grouped in the six classes alpha, beta, gamma, delta, sigma and epsilon, permits a vast number of putative receptor isoforms. The subunit composition of a particular receptor determines the specific effects of allosterical modulators of the GABAARs like benzodiazepines (BZs), barbiturates, steroids, some convulsants, polyvalent cations, and et…
Gene expression of neuregulin-1 isoforms in different brain regions of elderly schizophrenia patients
2010
One important risk gene in schizophrenia is neuregulin-1 (NRG1), which is expressed in different isoforms in the brain. To determine if alterations of NRG1 are present in schizophrenia, we measured gene expression of NRG1 and its main isoforms as well as the impact of genetic variation of NRG1 in an exploratory study examining three brain regions instead of only one as published so far. In all, we examined post-mortem samples from 11 schizophrenia patients and eight normal subjects. We investigated gene expression of total NRG1 and isoforms I, II and III by real-time PCR in the prefrontal cortex (Brodmann areas 9 and 10) and right hippocampal tissue. For the genetic study, we genotyped the …
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…
The b1 isoform of protocadherin-gamma (Pcdhgamma) interacts with the microtubule-destabilizing protein SCG10.
2004
Due to their structural characteristics and their diversity, the 22 members of the protocadherin-gamma (Pcdhgamma) family have been suggested to contribute to the establishment of specific connections in the nervous system. Here, we focus on a single isoform, Pcdhgamma-b1. Its expression is found in different brain regions and in developing spinal cord it is restricted to scattered cells, whereas all cells are labeled using an antibody that recognizes all Pcdhgamma isoforms. As a first step to understanding the signaling mechanisms downstream of Pcdhgamma, we identify the microtubule-destabilizing protein SCG10 as a cytoplasmic interactor for Pcdhgamma-b1 and other isoforms of the Pcdhgamma…