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PubMed2005

Cellular expression and alternative splicing of SLC25A23, a member of the mitochondrial Ca2+-dependent solute carrier gene family.

The transport of metabolites across the inner mitochondrial membrane is mediated by a large superfamily of mitochondrial solute carrier (MSC) proteins. A novel human member of the MSC gene family named SLC25A23, with homologs in mammalian and non-mammalian species has been recently identified together with two close paralogs, SLC25A24 and SLC25A25. These genes encode the human isoforms of the ATP-Mg/Pi carrier described in whole mitochondria. We report here the cellular expression and alternative splicing of SLC25A23. The gene encodes a 468 amino acids polypeptide, named SCaMC-3, with a bipartite structure typical of calcium-binding mitochondrial solute carrier (CaMSC) proteins. The amino-terminal portion harbors three canonical EF-hand calcium-binding domains while the carboxyl-terminal portion of SCaMC-3 has the characteristic features of the MSC superfamily. Northern blot analysis reveals the presence of the transcript in brain, heart, skeletal muscle, liver and small intestine. The SLC25A23 gene undergoes alternative splicing suggesting a modular nature of the encoded product. Three out of four putative protein isoforms lack a significant portion of the third mitochondrial carrier signature. The most common SCaMC-3 isoform shows a mitochondrial subcellular localization when transfected in HeLa cells and is able to bind calcium by Ca(2+)-dependent mobility shift assays. We believe that our study will contribute to a better knowledge of this family of mitochondrial carriers.

Alternative Splicing↗

PubMed1999

Increased levels of alternatively spliced interleukin 4 (IL-4delta2) transcripts in peripheral blood mononuclear cells from patients with systemic sclerosis.

Recent in vitro studies have shown that interleukin 4 (IL-4) induces and gamma interferon (IFN-gamma) inhibits collagen production. To define the TH1(IFN-gamma) and TH2(IL-4) cytokine profiles in systemic sclerosis (Sscl), a disease characterized by widespread fibrosis, we investigated IL-4 and IFN-gamma transcripts in peripheral blood mononuclear cells and plasma protein levels in 13 patients with Sscl. Two previously identified IL-4 transcripts, a full-length transcript and an alternatively spliced (truncated) transcript (designated IL-4delta2), were identified in patients and normal controls. Significantly increased levels of total IL-4 transcripts (full-length plus IL-4delta2 transcripts) were found in patients with Sscl in comparison to those found in healthy controls (P = 0.003), and this increase was primarily due to an increase in the level of the alternatively spliced IL-4delta2 form. The IL-4delta2/full-length-IL-4 transcript ratio was significantly increased in Sscl patients (P < 0.0001, versus healthy controls). Sequencing analysis revealed that the frequency of IL-4 clones carrying the IL-4delta2 transcript was also substantially increased in patients with Sscl. Plasma IL-4 protein levels were increased in Sscl patients compared to those in healthy controls (P = 0.001) and correlated with total IL-4 transcript levels. The up-regulation of the fibrogenic IL-4 (a TH2 cytokine) in Sscl suggests a pathogenic role for IL-4 in this disease.

Adult↗

PubMed1994

Studies on the structure of the mouse CBF-A gene and properties of a truncated CBF-A isoform generated from an alternatively spliced RNA.

CCAAT-binding factor (CBF), a heteromeric transcription factor that binds to sequences containing a CCAAT motif, is composed of three subunits, A, B and C, which are all required for DNA binding. The mouse CBF-A gene contains seven coding exons, which span 12 kb. Evidence is also presented for an additional 5' untranslated exon. The 90-amino-acid (aa) segment of CBF-A, which shows a high degree of sequence identity with the yeast transcription factor, HAP3, is split into exons 3 and 4. An alternatively spliced RNA that lacks exon 3 was identified by polymerase chain reaction. Although removal of exon 3 interrupts the CBF-A reading frame, a potential start codon at the 3' end of exon 2 is in the same reading frame as the reading frame encoding CBF-A in exons 4 to 7. A CBF-A polypeptide of the predicted 17-kDa, size, was indeed identified after in vitro transcription and translation of the DNA complementary to RNA (cDNA) corresponding to the alternatively spliced CBF-A mRNA. In contrast to full-length CBF-A, this truncated CBFA did not bind to a DNA sequence containing the CCAAT motif in the presence of the other two components of CBF. This result indicates that the segment corresponding to the exons missing in the truncated isoform of CBF-A is essential for the binding of CBF to DNA.

Alternative Splicing↗

PubMed1999

Structure, alternative splicing, and expression of the human RGS9 gene.

An isoform of RGS9 was recently identified as the GTPase activating protein in bovine and mouse rod and cone photoreceptors. To explore the potential role of the RGS9 gene in human retinal disease, we determined its exon/intron arrangement, and investigated its expression in human retina. The results show that the gene, located on 17q24, consists of 19 exons and spans more than 75kb of genomic DNA. The entire gene was found to be contained on a single BAC clone with an insert size of 170kb. The major transcripts of the gene are alternatively spliced into a 9.5kb retina-specific transcript (RGS9-1) and a brain specific 2.5kb transcript (RGS9-2). Exons 1-16 are constitutive and present in both variants. Exon 17 contains the 3' end of the open reading frame and the 3'-UTR of the RGS9-1 variant. In RGS9-2, exon 17 is alternatively spliced and joined to exons 18 and 19 that are not present in the retina variant. Immunolocalization with a monoclonal antibody recognizing the retina and brain variants shows abundant expression in photoreceptors and possibly very low levels in cell types of the inner retina. Owing to the specific expression of RGS9-1 in photoreceptors the RGS9 gene is a candidate gene for RP17, a form of autosomal retinitis pigmentosa, located on the long arm of chromosome 17.

Aged↗

PubMed1996

MAP2a, an alternatively spliced variant of microtubule-associated protein 2.

MAP2, a dendritically localized microtubule-associated protein (MAP), consists of a pair of high molecular mass (280 kDa) polypeptides, MAP2a and MAP2b, and several low molecular mass (70 kDa) proteins called MAP2c. Although MAP2b and MAP2c have been shown to arise via alternative splicing. It was not clear whether MAP2a is also created by alternative splicing or by posttranslational modification. Using epitope peptide mapping, we have demonstrated that an element specific to MAP2a is situated at its N-terminal end. A cDNA clone from an adult rat brain library was found to contain an additional 246 nucleotides situated at the 5' end of the 9-kb MAP2 mRNA. Antibodies generated against the encoded protein sequence recognize specifically MAP2a in rat brain homogenates. Moreover, although MAP2a, like MAP2b, is found in dendrites and cell bodies, its temporal appearance and cell type-specific distribution in rat brain differs from MAP2b.

Aging↗

PubMed2000

Detection of alternatively spliced variant messages of Fas gene and mutational screening of Fas and Fas ligand coding regions in peripheral blood mononuclear cells derived from silicosis patients.

Silicosis is clinically characterized not only by respiratory disorders but by immunological abnormalities such as the appearance of autoantibodies and complications of autoimmune diseases. Dysregulation of apoptosis, particularly in the Fas/Fas ligand (FasL) pathway, has been considered to play a role in the pathogenesis of autoimmune diseases. It has been found that serum soluble Fas (sFas) levels are elevated in silicosis patients (SIL) and the sFas message is dominantly expressed in peripheral blood mononuclear cells (PBMC) derived from these individuals. In the present study, one tried to detect alternatively spliced variant messages including typical sFas message and found four that were highly and frequently expressed, and which possess a signal peptide domain, but not transmembrane and signal transducing domains, in PBMC derived from SIL. Functional mutations were not detected in Fas and FasL genes in silicosis PBMC. Still, alternative spliced variants of the Fas gene including typical sFas message appear to play an important role in the immunological dysregulation in SIL.

Aged↗

PubMed2000

A trans-acting factor, isolated by the three-hybrid system, that influences alternative splicing of the amyloid precursor protein minigene.

Two clones were isolated in a three-hybrid screen of a rat fetal brain P5 cDNA library with an intronic splicing enhancer of the amyloid precursor protein (APP) gene as RNA bait. These clones represent the rat homologues of the previously described genes CUG-binding protein (CUG-BP) and Siah-binding protein (Siah-BP). Both interact in a sequence-specific manner with the RNA bait used for library screening as well as with the CUG repeat. In contrast, no interactions were observed in the three-hybrid assay with other baits tested. In two-hybrid assays, Siah-BP interacts with U2AF65 as well as with itself. EWS, an RGG-type RNA-binding protein associated with Ewing sarcoma, was identified as an interacting partner for the CUG-BP homologue in a two-hybrid assay for protein-protein interactions performed with various factors involved in RNA metabolism. Splicing assays performed by RT-PCR from cells cotransfected with certain cDNAs and an APP minigene, used as a reporter, indicate exclusion of exon 8 if the CUG-BP homologue is present. We conclude that clone AF169013 and its counterpart in human CUG-BP could be the trans-acting factors that interact with the splicing enhancer downstream of exon 8, and in this way influence alternative splicing of the APP minigene.

Alternative Splicing↗

PubMed2003

Regulation of ascidian Rel by its alternative splice variant.

The Rel/NF-kappaB family of transcription factors play key roles in morphogenesis and immune responses. We reported previously that As-rel1 and As-rel2 of the ascidian Halocynthia roretzi are involved in notochord formation. The As-rel1 protein is a typical Rel/NF-kappaB family member, whereas the As-rel2 protein is a novel truncated product of As-rel1 that lacks a nuclear localization signal and the unique C-terminal region. Here, we present conclusive evidence that As-rel1 and As-rel2 are generated from a single gene by alternative splicing. We analyzed the roles of As-rel2 using cells transfected with As-rel1 or As-rel2 or both. As-rel1 was localized in the nucleus and As-rel2 in the cytoplasm when they were transfected individually. In contrast, when they were transfected simultaneously, both were localized in the nucleus because of the association of As-rel2 with As-rel1. In this case, the transcriptional activity of As-rel1 was suppressed by As-rel2. Ascidian IkappaB was found to sequester As-rel1 in the cytoplasm and suppress its transcriptional activity when As-rel1 and IkappaB were transfected simultaneously. In contrast, when As-rel1 and IkappaB were transfected together with As-rel2, As-rel1 was transported into the nucleus and its transcriptional activity was rescued from inhibition by IkappaB, whereas As-rel2 remained localized in the cytoplasm, suggesting IkappaB sequestration in the cytoplasm by As-rel2. From these findings, we conclude that the alternative splice variant, As-rel2, regulates the nuclear localization and transcriptional activity of As-rel1.

Alternative Splicing↗

PubMed1992

The bovine protamine 2 gene: evidence for alternative splicing.

Protamine 2 (PRM2) is a low molecular weight arginine-rich protein which is present in haploid spermatogenic cells of human and mouse. Although the bull PRM2 gene is translated and transcribed at low levels, the protein could not be detected. The gene was isolated from a cosmid library and was found to consist of two exons (298 and 50 bp, respectively) interrupted by an intron of 142 bp. As compared to the PRM2 genes of man, mouse and rat the bovine gene lacks a highly conserved sequence coding for the amino acids RLHRIH. Furthermore, primer extension experiments on bull PRM2 mRNA and sequencing of junction fragments revealed alternative splicing of mRNA resulting in two putative isoforms of the protein. The most abundant transcript is spliced at the conserved splice donor site found in exon 1 at position 236 giving rise to an in-frame deletion of 63 bp as compared to the cDNA sequence (Maier et al. (1990) Nucleic Acids Res. 18, 1249-1254). The less abundant longer mRNA was not detectable by radioactive primer extension. The corresponding cDNA was obtained by performing PCR with reverse transcribed bull testis RNA or with a spermatid specific cDNA library. Alternative splicing should result in an addition of 21 nonpolar amino acids in the derived polypeptide and an altered protein conformation and function.

Alternative Splicing↗

PubMed1993

An effect of androgens on the length of the poly(A)-tail and alternative splicing cause size heterogeneity of the messenger ribonucleic acids encoding cystatin-related protein.

The 22-kilodalton glycoprotein, expressed in the rat ventral prostate under the influence of androgens, is structurally a cystatin-related protein (CRP), as has been shown by copy DNA sequencing. In fact, two slightly different forms (CRP-1 and CRP-2) are expressed in the prostate; one of them (CRP-1) is also expressed in the exorbital lacrymal gland. In both glands, the CRP-1 messenger RNA (mRNA)s are androgen regulated. Moreover, androgens also influence the size of these mRNAs, which show marked heterogeneity (from 760-950 nucleotides). Indeed, the smaller forms are predominant in castrated animals, whereas the large forms are observed immediately after androgen induction. Hybridization with oligo(dT) followed by ribonuclease H treatment revealed that differences in length of the poly(A)-tail are responsible for this effect of androgens. Indeed, two well defined forms of CRP mRNA subsisted after removal of the poly(A)-tail by this treatment. In the less abundant shorter form (CRP-1 delta), 123 nucleotides are deleted by alternative splicing at the junction between the third and the fourth exon. The variant mRNA encodes a truncated protein, wherein the last 27 amino acids are replaced by a hydrophobic stretch of 8 amino acids. No alternative splicing was observed for the CRP-2 mRNA.

Alternative Splicing↗

PubMed2006

The binding of DYNLL2 to myosin Va requires alternatively spliced exon B and stabilizes a portion of the myosin's coiled-coil domain.

The myosin Va light chain DYNLL2 has been proposed to function as an adaptor to link the myosin to certain cargo. Here, we mapped the binding site for DYNLL2 within the myosin Va heavy chain. Copurification and pull-down experiments showed that the heavy chain contains a single DYNLL2 binding site and that this site resides within a discontinuity in the myosin's central coiled-coil domain. Importantly, exon B, an alternatively spliced, three-amino acid exon, is a part of this binding site, and we show in the context of full-length myosin Va that this exon is required for DYNLL2-myosin Va interaction. We investigated the effect of DYNLL2 binding on the structure of a myosin Va heavy chain fragment that contains the DYNLL2 binding site and flanking sequence, only parts of which are strongly predicted to form a coiled coil. Circular dichroism measurements revealed a DYNLL2-induced change in the secondary structure of this dimeric myosin fragment that is consistent with an increase in alpha-helical coiled-coil content. Moreover, the binding of DYNLL2 considerably stabilizes this heavy chain fragment against thermal denaturation. Analytical ultracentrifugation yielded an apparent association constant of approximately 3 x 10(6) M(-1) for the interaction of DYNLL2 with the dimeric myosin fragment. Together, these data show that alternative splicing of the myosin Va heavy chain controls DYNLL2-myosin Va interaction and that DYNLL2 binding alters the structure of a portion of the myosin's coiled-coil domain. These results suggest that exon B could have a significant impact on the conformation and regulatory folding of native myosin Va, as well as on its interaction with certain cargos.

Alternative Splicing↗

PubMed1999

Human minibrain homologue (MNBH/DYRK1): characterization, alternative splicing, differential tissue expression, and overexpression in Down syndrome.

The human homologue (MNBH/DYRK1) of the Drosophila minibrain gene maps to human chromosome 21 within the Down syndrome (DS) critical region and is within the region minimally deleted in chromosome 21-linked microcephaly. As a first step in gaining insight into the role that MNBH may have in human neurogenesis, and as a lead-up to the development of mouse models for MNBH overexpression, we have characterized the gene at the molecular level. We describe here the MNBH full-length transcript, alternative splicing, expression profile, and genomic organization. The full-length cDNA of MNBH is 5. 2 kb and is composed of 17 exons spanning 150 kb, between markers D21S335 and D21S337. Transcripts MNBHa and MNBHb arise from the use of different first exons in the 5'-UTR and are differentially expressed. MNBHa is expressed ubiquitiously in a broad spectrum of tissues and is apparently under the control of a CpG island. MNBHb is expressed only in heart and skeletal muscle and is apparently under the control of a TATA-like box. Four alternative splicing events affecting the C-terminus of the protein yield at least four isoforms of MNBH (MNBH-iso1, MNBH-iso2, MNBH-iso3, and MNBH-iso4). A PEST sequence, potentially involved in the rapid degradation of the protein, is present in all the isoforms. A histidine repeat and a serine/threonine domain are present only in the largest form of the protein (MNBH-iso1). MNBH was overexpressed 1.5-fold in DS brains and Dyrk1 about 2.1-fold in the brains of the Ts65Dn mice. The information provided here should be valuable for MNBH mutation studies and aid in the development of DS animal models.

3' Untranslated Regions↗

PubMed2006

PKCdelta alternatively spliced isoforms modulate cellular apoptosis in retinoic acid-induced differentiation of human NT2 cells and mouse embryonic stem cells.

NT2 cells are a human teratocarcinoma cell line that, upon treatment with retinoic acid (RA), begin differentiating into a neuronal phenotype. The transformation of undifferentiated NT2 cells into hNT neurons presents an opportunity to investigate the mechanisms involved in neurogenesis because a key component is cell apoptosis, which is essential for building neural networks. Protein kinase Cdelta (PKCdelta) plays an important role as a mediator of cellular apoptosis in response to various stimuli. PKCdelta (deltaI) is proteolytically cleaved at its hinge region (V3) by caspase 3 and the catalytic fragment is sufficient to induce apoptosis in various cell types. Mouse PKCdeltaII is rendered caspase resistant due to an insertion of 78 bp within the caspase recognition site in its V3 domain. No functional role has been attributed to these alternatively spliced variants of PKCdelta. We sought to find a correlation between the onset of apoptosis, neurogenesis, and the expression of PKCdelta isoforms. Our results indicate that RA regulates the expression of PKCdelta alternative splicing variants in NT2 cells. Further, overexpression of PKCdeltaI promotes apoptosis while PKCdeltaII overexpression shields the cells from apoptosis. This is the first report to attribute physiological function to PKCdeltaI and -deltaII isoforms. Next we demonstrated that mouse embryonic stem cells differentiate in vitro into dopaminergic neurons upon stimulation with RA and ciliary neurotrophic factor. These cells showed a simultaneous increase in tyrosine hydroxylase and PKCdeltaII expression. We suggest that the molecular mechanisms regulating differentiation and apoptosis could be understood by alternative expression of PKCdelta isoforms.

Alternative Splicing↗

PubMed1993

Molecular cloning of a developmentally regulated brain protein, chicken drebrin A and its expression by alternative splicing of the drebrin gene.

Drebrins are developmentally regulated proteins found in the chicken brain and are classified into three forms, E1, E2 and A. Previously we isolated two cDNAs corresponding to the embryonic drebrin mRNAs from a chick embryo cDNA library. They differed in that an internal 129-nucleotide sequence, designated ins1, was inserted in the cDNA encoding drebrin E2 and was deleted in the other cDNA encoding drebrin E1. To search for the cDNA clone encoding drebrin A, a cDNA library of 1-day-old chick brains was screened using embryonic drebrin cDNA fragments as probes. Consequently, a novel cDNA was isolated, the sequence of which was entirely identical with that of drebrin E2 except for the insertion of a 138-nucleotide sequence, designated ins2, in the 5' direction immediately upstream from ins1. Since the translation product of the entire coding region was similar to that of drebrin A, this cDNA should correspond to the mRNA for drebrin A. Sequencing analysis of three drebrin cDNAs clearly indicated that the heterogeneity of chicken drebrins was caused by the insertion or deletion of the two sequences, ins1 and ins2. The amino-terminal half region including ins2 and two short sequences in the carboxyl-terminal region of the predicted drebrin A were highly evolutionarily conserved. Cloning and sequencing of the drebrin gene revealed that ins1 and ins2 were independently encoded by separate exons and three drebrin isoforms were thought to arise by alternative splicing from a single drebrin gene. The difference in the time course of expression and tissue distribution of each drebrin suggests that the machinery of alternative splicing site selection of the drebrin gene is regulated in a developmental stage-dependent and tissue-specific manner.

Alternative Splicing↗

PubMed1994

Identification of a novel type of alternative splicing of a tyrosine kinase receptor. Juxtamembrane deletion of the c-met protein kinase C serine phosphorylation regulatory site.

We have detected a novel type of structural variant of the tyrosine kinase receptor for c-met, also known as the hepatocyte growth factor receptor, in mouse tissues. The cDNA of the variant transcript of c-met lacks 141 base pairs, which predicts an in-frame deletion of 47 amino acids in the juxtamembrane region of the cytoplasmic domain. Sequence analysis of genomic DNA containing the c-met locus revealed that the absence of a discrete exon is responsible for this 141-base pair deletion and that alternative splicing leads to production of two forms of transcript. These two forms of transcript are designated as c-metsm (for small) and c-metlg (for large) to distinguish the absence or presence of the 141-base pair segment, respectively. The c-metsm variant is present in adult mouse tissues including kidney, liver, and brain as well as in 9-10-day-old embryos. In all cases, expression of c-metsm was lower than that of the normal transcript, c-metlg. An antiserum against mouse c-Met protein immunoprecipitated corresponding protein forms of approximately 152 and approximately 145 kDa from whole kidney lysate under reducing conditions. The size difference of approximately 7 kDa between these isoforms corresponds to the predicted difference of 47 amino acids. The presence of this shorter variant transcript and its corresponding protein isoform in a variety of normal tissues suggests a physiological role. The deleted region in the cytoplasmic domain of c-metsm contains a sequence motif (S985ARS) for protein kinase C phosphorylation that has recently been shown to play a key role in the down-regulation of hepatocyte growth factor receptor kinase activity. The identification of this novel isoform, c-metsm, demonstrates that a tyrosine kinase receptor can achieve additional diversity by alternative splicing at a key regulatory site in its cytoplasmic domain.

Alternative Splicing↗

PubMed1992

Alternative splicing of HLA-G transcripts yields proteins with primary structures resembling both class I and class II antigens.

We have investigated HLA-G mRNA expression in cells and tissues expressing the gene. This analysis has demonstrated that the HLA-G primary transcript is alternatively spliced to yield at least three distinct mature mRNAs. Sequencing of the transcripts has shown that the largest mRNA is essentially that previously characterized, encoding a leader sequence, three external domains, a transmembrane region, and a cytoplasmic sequence. Of the two smaller messages, a 900-base mRNA does not include exon 3, resulting in a predicted protein sequence with the alpha 1 and alpha 3 external domains joined. The smallest mRNA results from splicing out exons 3 and 4, connecting the alpha domain directly to the transmembrane sequence. Alternative splicing of HLA-G mRNA was found in placental tissues and in eye tissue as well as in HLA-G-transfected cell lines. In term placental tissue the smallest mRNA appeared to be more abundant than the full-length form, while in a cell line derived from an earlier developmental stage the larger form predominated. Immunoprecipitation of [35S]methionine-labeled cell lysates showed that three different HLA-G proteins were present in transfected cells, with sizes corresponding to those predicted from the three alternative mRNA sequences. These findings are discussed in terms of potential functions of the alternative HLA-G proteins.

Amino Acid Sequence↗

PubMed2000

Developmental differences in alternative splicing of the NR1 protein in rat cortex and cerebellum.

Expression of the C-terminal cassettes of the NR1 protein was examined using a quantitative Western blot method with cassette-specific antibodies. Measurements were made of the percent of total NR1 protein that contained a specific cassette in both the cerebellum and cortex over development. In the cortex, the C1 cassette was shown to be present in about half of total NR1 protein with no change over development. While about half of total NR1 in the cerebellum at postnatal day 42 (P42) contained the C1 cassette, little NR1 protein with this cassette was seen at young ages. In both the cerebellum and cortex, the C2 and C2' cassettes showed opposite developmental patterns, with the C2 cassette decreasing and the C2' cassette increasing over age. Together with previous data on the expression of the N1 cassette, this study describes the alternatively spliced forms of NR1 protein that are dominant at different ages. In the young cerebellum, the NR1(001) form appeared dominant, while in the young cortex there appeared to be a mix of NR1(001) and NR1(011). The most common splice forms of NR1 protein in the adult cerebellum appeared to be NR1(111) and NR1(100). In the adult cortex, there appeared to be a mix of NR1(001) and NR1(011). These data on the expression of the alternatively spliced forms of NR1 allow predictions on the possible characteristics of NMDA receptors in different regions at specific ages.

Aging↗

PubMed2002

Identification of an alternatively spliced isoform of the common cytokine receptor gamma chain in chickens.

The common cytokine receptor gamma(gamma(c)) chain is shared by at least six cytokine receptors and plays a critical role in the regulation of immune responses. In this study, we discovered that, unlike mammals, chickens possess two different gamma(c) gene transcripts, chgamma(c)-a and chgamma(c)-b. Sequence comparisons between the cDNAs and a gamma(c) genomic clone isolated by PCR revealed that chgamma(c)-b contained an in-frame 78bp insertion between Gly-222 and Val-223 of the chgamma(c)-a sequence. This insertion most likely resulted from alternative splicing such that the fifth intron was not removed from the chgamma(c)-b transcript. Furthermore, while chgamma(c)-a and chgamma(c)-b transcripts were expressed equally in the spleen, thymus, bursa, and cecal tonsils, they were differentially expressed during the time course of Con A stimulation of splenic T lymphocytes. Western blot analysis of normal spleen lymphocytes identified 45, 53, and 64 kDa immunoreactive bands whereas only 64kDa band was detected in Con A-activated splenic lymphocytes. COS-7 cells transfected with chgamma(c)-b secreted approximately 42kDa proteins. Taken together, our results document that chickens express an alternative spliced gamma(c) receptor which is larger than the conventional transcript and this novel isoform generates soluble receptors in the transfected COS-7 cells.

Alternative Splicing↗