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Alternative Splice Variants (alternative + splice_variants)
Selected AbstractsExpression of PRiMA in the mouse brain: membrane anchoring and accumulation of ,tailed' acetylcholinesteraseEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2003Noël A. Perrier Abstract We analysed the expression of PRiMA (proline-rich membrane anchor), the membrane anchor of acetylcholinesterase (AChE), by in situ hybridization in the mouse brain. We compared the pattern of PRiMA transcripts with that of AChE transcripts, as well as those of choline acetyltransferase and M1 muscarinic receptors which are considered pre- and postsynaptic cholinergic markers. We also analysed cholinesterase activity and its molecular forms in several brain structures. The results suggest that PRiMA expression is predominantly or exclusively related to the cholinergic system and that anchoring of cholinesterases to cell membranes by PRiMA represents a limiting factor for production of the AChE tailed splice variant (AChET),PRiMA complex, which represents the major AChE component in the brain. This enzyme species is mostly associated with cholinergic neurons because the pattern of PRiMA mRNA expression largely coincides with that of ChAT. We also show that, in both mouse and human, PRiMA proteins exist as two alternative splice variants which differ in their cytoplasmic regions. [source] The interferon alpha induced protein ISG12 is localized to the nuclear membraneFEBS JOURNAL, Issue 22 2001Pia M. Martensen Interferons exert their biological function mainly through the activation of interferon-stimulated genes (ISGs). ISG12 (originally designated p27) belongs to a family of small, interferon , inducible genes of unknown function. We have determined the 5, end sequence of ISG12 cDNA from the human cell lines HeLa and AMA by RACE. Comparing this sequence to ISG12 sequences in the expressed sequence tag (EST) database revealed the presence of two alternative splice variants of ISG12 in human cells exhibiting the same open reading frame. We have sequenced the promoter region of the ISG12 gene and found ISRE, IRF1/IRF2, and STAT elements correlating to the interferon , inducibility of the gene. Subsequently, we have expressed human ISG12, a 12-kDa hydrophobic protein in the baculovirus expression system and with a C-terminal FLAG-tag in the human cell line 293. Recombinant ISG12 sediments in the nuclear envelope in both cell types. Finally, we have been able to demonstrate the prevalence of the ISG12 gene product in the nuclear envelope of HeLa cells treated with interferon , by immunocytochemical analyses. ISG12 is the first interferon induced protein found localizing to the nuclear envelope. [source] Distinct expression patterns of the immunogenic differentiation antigen NY-BR-1 in normal breast, testis and their malignant counterpartsINTERNATIONAL JOURNAL OF CANCER, Issue 7 2008Jean-Philippe Theurillat Abstract NY-BR-1 is a differentiation antigen and a potential target for cancer immunotherapy. Its mRNA expression is restricted to breast, testis, prostate and breast cancer by RT-PCR. In this study, we correlated NY-BR-1 protein and mRNA expression on tissue microarrays of mammary, prostatic and testicular malignancies using immunohistochemisty and in situ hybridization with probes for exon 4,7 and 30,33. NY-BR-1 mRNA was confined to primary spermatocytes, suggesting a role in spermatogenesis. Exon 4,7 and 30,33 were equally expressed this cell type. However, NY-BR-1 was absent in all germ cell tumours analyzed (n = 475) and present in one of 56 (2%) prostate carcinomas. In breast, NY-BR-1 mRNA expression was detected in 307 of 442 (70%) primary carcinomas, with strong correlation to its protein expression (p < 0.0001). mRNA expression was significantly stronger and more frequently detected by the exon 30,33 probe than by the exon 4,7 probe (70% vs. 35%, p < 0.0001), indicating the presence of alternative splice variants that lack 5-prime sequences. A similar restricted mRNA pattern was also observed in the normal breast epithelium. NY-BR-1 protein and mRNA correlated significantly with estrogen receptor , (ER,) protein expression (p < 0.0001), with stronger association to NY-BR-1 mRNA than protein (odds ratio 7.7 compared to 4.6). We identified 4 estrogen response elements (ERE)-like sequences nearby the promoter region, suggesting that NY-BR-1 transcription might be controlled by ER,. Accordingly, analysis of matching pairs of primary tumors with their recurrences showed a marked decrease of NY-BR-1 expression in recurrences after tamoxifen treatment (p < 0.0001). © 2007 Wiley-Liss, Inc. [source] Alternative isoforms of myelin/oligodendrocyte glycoprotein with variable cytoplasmic domains are expressed in human brainJOURNAL OF NEUROCHEMISTRY, Issue 2 2007Chantal Allamargot Abstract The human myelin/oligodendrocyte glycoprotein (MOG) gene is encoded by 10 exons that exhibit a complex pattern of alternative splicing. This report demonstrates that several MOG-specific alternative splice variants are indeed expressed in human oligodendrocytes (OLs) and myelin during perinatal development and are retained through adulthood. While all forms possess the common extracellular Ig-like domain, these alternative MOG structures differ significantly in their respective cytoplasmic domains. Peptide-specific antibodies were generated to facilitate detection of these different MOG moieties. The fidelity of these antibodies is shown using N20 OLs expressing individual MOG variants. These antibodies also only co-localize with another well-characterized marker of OLs and myelin , PLP/DM20 proteins. Among the human tissue samples tested, very limited expression occurred by 36 weeks gestation for 2,3 MOG variants, and the remaining MOG isoforms were not evident until shortly after birth. This study represents the first evidence of alternative translation products from the MOG gene. To date, it is believed that alternative splicing of MOG is limited to primates. Recent completion of various genome projects has revealed that alternative splicing is much more prevalent than originally estimated, and species-specific alternative splicing is now being shown to be highly relevant to expanding proteomic diversity. [source] Analysis of the mRNA expression of the TGF-Beta family in testicular cells and localization of the splice variant TGF-,2B in testisMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 10 2006Lutz Konrad Abstract The transforming growth factors (TGF)-,, TGF-,1, TGF-,2, and TGF-,3, and their receptors [T,RI, T,RII, T,RIII (betaglycan)] elicit many functions in the testis, for example, they perturb the blood testis barrier (BTB). Although expression of the ligands and receptors have been investigated, the alternative splice variants are incompletely examined. We therefore have analyzed all ligands, the receptors, and the splice variants T,RIB, T,RIIB, and TGF-,2B in testicular cells from rat and mouse. In mouse, the novel transcript variant TGF-,2B was identified and was found in Leydig cells, spermatogonia, pachytene spermatocytes, and in the apical regions of the Sertoli cells in adult testis. Even though expression of the splice variant T,RIB could be shown in mouse and rat, we never found the isoform T,RIIB in the rat cell lines studied. Whereas in all testicular cells expression of all TGF-, ligands could be shown, receptor mRNA expression was slightly more diverse. Furthermore, expression pattern of the splice variants was more heterogeneous, for example, T,RIB was not detectable in adult Sertoli cells, primary peritubular cells, and immortalized peritubular cells. The heterogeneous expression of the receptors and especially of the splice variants might provide possible clues for the different functions of the TGF-, ligands in testicular cells. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source] Human MIP synthase splice variants in bipolar disorderBIPOLAR DISORDERS, Issue 7 2007Alon Shamir Objectives:, Alternative splicing allows the production of multiple gene products with different functions from a given sequence, affecting cellular function control. Tissue-specific splicing is most prevalent in the brain. We therefore investigate whether splice variants contribute to complex psychiatric disorders. A database search suggested that the myo -inositol-1-phosphate (MIP) synthase gene, possibly involved in pathophysiology of bipolar disorder, has splice variants. Methods:, Human RNA was purified from lymphocytes and postmortem brain. MIP synthase alternative splice variants were amplified using reverse transcription-polymerase chain reaction. Results:, The bioinformatics finding was confirmed in both tissues. No difference in lymphocyte MIP synthase mRNA splice-variant levels was found between bipolar patients and controls. However, patients with family history of a major psychiatric disorder had significantly higher levels of the variant lacking exons 3 and 4 versus patients with no family history and controls. Conclusions:, As alternative splicing may be a mechanism by which the ,30,000 genes are amplified in mammalian brain, further studies with other candidate genes for psychiatric disorders are needed. [source] | |||||||||||||