RNA-binding protein involved in the regulation of pre-mRNA alternative splicing. Mediates exon inclusion and/or exclusion in pre-mRNA that are subject to tissue-specific and developmentally regulated alternative splicing. Specifically activates exon 5 inclusion of cardiac isoforms of TNNT2 during heart remodeling at the juvenile to adult transition. Activates the splicing of MAPT/Tau exon 10. Binds to muscle-specific splicing enhancer (MSE) intronic sites flanking the alternative exon 5 of TNNT2 pre-mRNA.
Alternative splicing of cardiac troponin T (cTNT) exon 5 undergoes a developmentally regulated switch such that exon inclusion predominates in embryonic, but not adult, striated muscle. We previously described four muscle-specific splicing enhancers (MSEs) within introns flanking exon 5 in chicken cTNT that are both necessary and sufficient for exon inclusion in embryonic muscle. We also demonstrated that CUG-binding protein (CUG-BP) binds a conserved CUG motif within a human cTNT MSE and positively regulates MSE-dependent exon inclusion. Here we report that CUG-BP is one of a novel family of developmentally regulated RNA binding proteins that includes embryonically lethal abnormal vision-type RNA binding protein 3 (ETR-3). This family, which we call CELF proteins for CUG-BP- and ETR-3-like factors, specifically bound MSE-containing RNAs in vitro and activated MSE-dependent exon inclusion of cTNT minigenes in vivo. The expression of two CELF proteins is highly restricted to brain. CUG-BP, ETR-3, and CELF4 are more broadly expressed, and expression is developmentally regulated in striated muscle and brain. Changes in the level of expression and isoforms of ETR-3 in two different developmental systems correlated with regulated changes in cTNT splicing. A switch from cTNT exon skipping to inclusion tightly correlated with induction of ETR-3 protein expression during differentiation of C2C12 myoblasts. During heart development, the switch in cTNT splicing correlated with a transition in ETR-3 protein isoforms. We propose that ETR-3 is a major regulator of cTNT alternative splicing and that the CELF family plays an important regulatory role in cell-specific alternative splicing during normal development and disease.
J. Neurochem. 88, 1078-1090 (2004)[PubMed:15009664]
Tau is a microtubule-associated protein whose transcript undergoes complex regulated splicing in the mammalian nervous system. In humans, exon 10 of the gene is an alternatively spliced cassette which is adult-specific and which codes for a microtubule binding domain. Mutations that affect splicing of exon 10 have been shown to cause inherited frontotemporal dementia (FTDP). In this study, we reconstituted naturally occurring exon 10 FTDP mutants and classified their effects on its splicing. We also carried out a comprehensive survey of the influence of splicing regulators on exon 10 inclusion and tentatively identified the site of action for several of these factors. Lastly, we identified the domains of regulators SWAP and hnRNPG, which are required for regulation of exon 10 splicing.
Interacting selectively and non-covalently with messenger RNA (mRNA), an intermediate molecule between DNA and protein. mRNA includes UTR and coding sequences, but does not contain introns.
Alternative splicing of cardiac troponin T (cTNT) exon 5 undergoes a developmentally regulated switch such that exon inclusion predominates in embryonic, but not adult, striated muscle. We previously described four muscle-specific splicing enhancers (MSEs) within introns flanking exon 5 in chicken cTNT that are both necessary and sufficient for exon inclusion in embryonic muscle. We also demonstrated that CUG-binding protein (CUG-BP) binds a conserved CUG motif within a human cTNT MSE and positively regulates MSE-dependent exon inclusion. Here we report that CUG-BP is one of a novel family of developmentally regulated RNA binding proteins that includes embryonically lethal abnormal vision-type RNA binding protein 3 (ETR-3). This family, which we call CELF proteins for CUG-BP- and ETR-3-like factors, specifically bound MSE-containing RNAs in vitro and activated MSE-dependent exon inclusion of cTNT minigenes in vivo. The expression of two CELF proteins is highly restricted to brain. CUG-BP, ETR-3, and CELF4 are more broadly expressed, and expression is developmentally regulated in striated muscle and brain. Changes in the level of expression and isoforms of ETR-3 in two different developmental systems correlated with regulated changes in cTNT splicing. A switch from cTNT exon skipping to inclusion tightly correlated with induction of ETR-3 protein expression during differentiation of C2C12 myoblasts. During heart development, the switch in cTNT splicing correlated with a transition in ETR-3 protein isoforms. We propose that ETR-3 is a major regulator of cTNT alternative splicing and that the CELF family plays an important regulatory role in cell-specific alternative splicing during normal development and disease.
Interacting selectively and non-covalently with a nucleotide, any compound consisting of a nucleoside that is esterified with (ortho)phosphate or an oligophosphate at any hydroxyl group on the ribose or deoxyribose.
Elucidating the mechanisms of alternative splicing in the brain is a prerequisite to the understanding of the pathogenesis of major neurological diseases linked to impairment of pre-mRNA alternative splicing. The gene trinucleotide repeat-containing 4 (TNRC4) is predicted to encode a member of the CELF (CUG-BP- and ETR-3-like factors) family of RNA-binding proteins containing a 15-18-residue polyglutamine sequence. The TNRC4 transcript is selectively expressed in the brain. Using an anti-peptide antibody against the predicted sequence, we establish the presence of TNRC4 as a approximately 50 kDa protein in the brain. Full-length TNRC4 displays nuclear and cytoplasmic localizations in transfected cells, whereas a C-terminally truncated mutant is essentially confined to the cytoplasm. TNRC4 is not recruited into inclusions formed by polyglutamine-expanded ataxin-1 or huntingtin. TNRC4 activates tau exon 10 (E10) inclusion at high efficiency in transfected cells. TNRC4 contains two consecutive N-terminal RNA recognition motifs (RRMs) separated from the C-terminal RRM. Deletion and point mutant analysis show that the activity of TNRC4 on tau E10 splicing is mainly mediated by the RNA-binding activity of the second RRM and involves an intronic element of the tau pre-mRNA. The polyglutamine sequence has no effect on the activity of TNRC4 on tau E10 splicing. This study represents the first characterization of TNRC4 and provides further insight into the mechanisms of brain-specific alternative splicing and their possible pathological implications.
The joining together of exons from one or more primary transcripts of messenger RNA (mRNA) and the excision of intron sequences, via a spliceosomal mechanism, so that mRNA consisting only of the joined exons is produced.
Alternative splicing of cardiac troponin T (cTNT) exon 5 undergoes a developmentally regulated switch such that exon inclusion predominates in embryonic, but not adult, striated muscle. We previously described four muscle-specific splicing enhancers (MSEs) within introns flanking exon 5 in chicken cTNT that are both necessary and sufficient for exon inclusion in embryonic muscle. We also demonstrated that CUG-binding protein (CUG-BP) binds a conserved CUG motif within a human cTNT MSE and positively regulates MSE-dependent exon inclusion. Here we report that CUG-BP is one of a novel family of developmentally regulated RNA binding proteins that includes embryonically lethal abnormal vision-type RNA binding protein 3 (ETR-3). This family, which we call CELF proteins for CUG-BP- and ETR-3-like factors, specifically bound MSE-containing RNAs in vitro and activated MSE-dependent exon inclusion of cTNT minigenes in vivo. The expression of two CELF proteins is highly restricted to brain. CUG-BP, ETR-3, and CELF4 are more broadly expressed, and expression is developmentally regulated in striated muscle and brain. Changes in the level of expression and isoforms of ETR-3 in two different developmental systems correlated with regulated changes in cTNT splicing. A switch from cTNT exon skipping to inclusion tightly correlated with induction of ETR-3 protein expression during differentiation of C2C12 myoblasts. During heart development, the switch in cTNT splicing correlated with a transition in ETR-3 protein isoforms. We propose that ETR-3 is a major regulator of cTNT alternative splicing and that the CELF family plays an important regulatory role in cell-specific alternative splicing during normal development and disease.
J. Neurochem. 88, 1078-1090 (2004)[PubMed:15009664]
Tau is a microtubule-associated protein whose transcript undergoes complex regulated splicing in the mammalian nervous system. In humans, exon 10 of the gene is an alternatively spliced cassette which is adult-specific and which codes for a microtubule binding domain. Mutations that affect splicing of exon 10 have been shown to cause inherited frontotemporal dementia (FTDP). In this study, we reconstituted naturally occurring exon 10 FTDP mutants and classified their effects on its splicing. We also carried out a comprehensive survey of the influence of splicing regulators on exon 10 inclusion and tentatively identified the site of action for several of these factors. Lastly, we identified the domains of regulators SWAP and hnRNPG, which are required for regulation of exon 10 splicing.
Alternative splicing of cardiac troponin T (cTNT) exon 5 undergoes a developmentally regulated switch such that exon inclusion predominates in embryonic, but not adult, striated muscle. We previously described four muscle-specific splicing enhancers (MSEs) within introns flanking exon 5 in chicken cTNT that are both necessary and sufficient for exon inclusion in embryonic muscle. We also demonstrated that CUG-binding protein (CUG-BP) binds a conserved CUG motif within a human cTNT MSE and positively regulates MSE-dependent exon inclusion. Here we report that CUG-BP is one of a novel family of developmentally regulated RNA binding proteins that includes embryonically lethal abnormal vision-type RNA binding protein 3 (ETR-3). This family, which we call CELF proteins for CUG-BP- and ETR-3-like factors, specifically bound MSE-containing RNAs in vitro and activated MSE-dependent exon inclusion of cTNT minigenes in vivo. The expression of two CELF proteins is highly restricted to brain. CUG-BP, ETR-3, and CELF4 are more broadly expressed, and expression is developmentally regulated in striated muscle and brain. Changes in the level of expression and isoforms of ETR-3 in two different developmental systems correlated with regulated changes in cTNT splicing. A switch from cTNT exon skipping to inclusion tightly correlated with induction of ETR-3 protein expression during differentiation of C2C12 myoblasts. During heart development, the switch in cTNT splicing correlated with a transition in ETR-3 protein isoforms. We propose that ETR-3 is a major regulator of cTNT alternative splicing and that the CELF family plays an important regulatory role in cell-specific alternative splicing during normal development and disease.
The process of removing sections of the primary RNA transcript to remove sequences not present in the mature form of the RNA and joining the remaining sections to form the mature form of the RNA.
Evidence
1:
Inferred from Mutant PhenotypeUniProtKB
Elucidating the mechanisms of alternative splicing in the brain is a prerequisite to the understanding of the pathogenesis of major neurological diseases linked to impairment of pre-mRNA alternative splicing. The gene trinucleotide repeat-containing 4 (TNRC4) is predicted to encode a member of the CELF (CUG-BP- and ETR-3-like factors) family of RNA-binding proteins containing a 15-18-residue polyglutamine sequence. The TNRC4 transcript is selectively expressed in the brain. Using an anti-peptide antibody against the predicted sequence, we establish the presence of TNRC4 as a approximately 50 kDa protein in the brain. Full-length TNRC4 displays nuclear and cytoplasmic localizations in transfected cells, whereas a C-terminally truncated mutant is essentially confined to the cytoplasm. TNRC4 is not recruited into inclusions formed by polyglutamine-expanded ataxin-1 or huntingtin. TNRC4 activates tau exon 10 (E10) inclusion at high efficiency in transfected cells. TNRC4 contains two consecutive N-terminal RNA recognition motifs (RRMs) separated from the C-terminal RRM. Deletion and point mutant analysis show that the activity of TNRC4 on tau E10 splicing is mainly mediated by the RNA-binding activity of the second RRM and involves an intronic element of the tau pre-mRNA. The polyglutamine sequence has no effect on the activity of TNRC4 on tau E10 splicing. This study represents the first characterization of TNRC4 and provides further insight into the mechanisms of brain-specific alternative splicing and their possible pathological implications.
Protein involved in the processing of the primary mRNA transcript to yield a functional mRNA. This includes 5' capping, 3' cleavage and polyadenylation, as well as mRNA splicing and RNA editing.
Protein involved in the process by which nonsense sequences or intervening sequences (introns) are removed from pre-mRNA to generate a functional mRNA (messenger RNA) that contains only exons.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.