Search results for "Protein Isoforms"
showing 10 items of 175 documents
Functional analysis of the isoforms of an ABI3-like factor of Pisum sativum generated by alternative splicing
2009
At least seven isoforms (PsABI3-1 to PsABI3-7) of a putative, pea ABI3-like factor, originated by alternative splicing, have been identified after cDNA cloning. A similar variability had previously only been described for monocot genes. The full-length isoform, PsABI3-1, contains the typical N-terminal acidic domains and C-terminal basic subdomains, B1 to B3. Reverse transcriptase-PCR analysis revealed that the gene is expressed just in seeds, starting at middle embryogenesis; no gene products are observed in embryo axes after 18 h post-imbibition although they are more persistent in cotyledons. The activity of the isoforms was studied by yeast one-hybrid assays. When yeast was transformed …
New perspectives on the renal slit diaphragm protein podocin.
2011
Podocin is a critical component of the glomerular filtration barrier, its mutations causing recessive steroid-resistant nephrotic syndrome. A GenBank analysis of the human podocin (NPHS2) gene resulted in the possible existence of a new splice variant of podocin in the kidney, missing the in-frame of exon 5, encoding the prohibitin homology domain. Using RT–polymerase chain reaction and immunoblotting followed by sequence analysis, we are for the first time able to prove the expression of a novel podocin isoform (isoform 2), exclusively and constitutively expressed in human podocytes. Furthermore, we reveal singular extrarenal podocin expression in human and murine testis. Our data show the…
WT1 isoform expression pattern in acute myeloid leukemia.
2013
WT1 plays a dual role in leukemia development, probably due to an imbalance in the expression of the 4 main WT1 isoforms. We quantify their expression and evaluate them in a series of AML patients. Our data showed a predominant expression of isoform D in AML, although in a lower quantity than in normal CD34+ cells. We found a positive correlation between the total WT1 expression and A, B and C isoforms. The overexpression of WT1 in AML might be due to a relative increase in A, B and C isoforms, together with a relative decrease in isoform D expression.
Differential apolipoprotein(a) isoform expression in heterozygosity is an independent contributor to lipoprotein(a) levels variability
2003
Abstract Background and methods : Lipoprotein(a) [Lp(a)] levels represent an independent risk factor for cardio- and cerebrovascular diseases. Since lipoprotein(a) levels show a wide variability even in subjects with similar apolipoprotein(a) isoforms, we investigated the contribution of apolipoprotein(a) heterozygosity to lipoprotein(a) variance. Lipoprotein(a) levels, apolipoprotein(a) isoforms identification and expression, and the correlation with other lipo-apolipoprotein parameters have been investigated in 628 subjects >18 years of age. Results : In our study, 246 subjects were found heterozygous for apolipoprotein(a) isoforms. Lipoprotein(a) levels were higher in females. About 40% …
Expression analysis and functional activity of interleukin-7 splice variants.
2008
Alternative splicing results in multiple protein isoforms derived from a single gene. The magnitude of this process ranges from a complete loss of function to gain of new function. We examined, as a paradigm, alternative splicing of the non-redundant human cytokine, interleukin-7 (IL-7). We show that extensive IL-7 splicing in human tissues of different histology, including MTB+ granuloma lesions, transformed tissue and tumor cell lines. IL-7 splice variants were expressed as recombinant proteins. A differentially spliced IL-7 isoform, lacking exon 5, leads to STAT-5 phosphorylation in CD4+ and CD8+ T cells, promotes thymocyte maturation and T-cell survival. Human tumor lesions show aberran…
RNA-binding activity of the rat calmodulin-binding PEP-19 protein and of the long PEP-19 isoform
2012
Synthesis of H1˚ histone protein, in the developing rat brain, seems to be regulated mainly at the post-transcriptional level. Since regulation of RNA metabolism depends on a series of RNA-binding proteins, we have been searching for RNA-binding proteins involved in the post-transcriptional regulation of the H1˚ gene. We recently reported isolation, from a cDNA expression library, of an insert encoding a novel protein, the C-terminal half of which is identical to that of PEP-19, a brain-specific protein involved in calcium metabolism. The novel protein was called long PEP-19 isoform (LPI). Herein we show that LPI, as well as PEP-19, can bind H1˚ RNA. Moreover, in order to improve production…
NAIP-deltaEx10-11: a novel splice variant of the apoptosis inhibitor NAIP differently expressed in drug-sensitive and multidrug-resistant HL60 leukem…
2002
Alterations of neuronal apoptosis inhibitory protein (NAIP), a member of the inhibitory of apoptosis protein (IAP) family of inhibitors of apoptosis, have been previously associated with different neurodegenerative disorders. This study indicated the existence of a novel NAIP splice variant. This isoform, NAIP-deltaEx10-11, was found in tumor cell lines of different origin and in normal adult brain. Analysis of the putative protein predicted that the NAIP variant lacks part of the third BIR domain as well as the COOH-terminal tail of regular NAIP. This might suggest that it is endowed with a reduced antiapoptotic activity. This view is supported by the fact that NAIP-deltaEx10-11 mRNA and p…
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…