Sex-specific alternative splicing of RNA from the transformer gene results from sequence-dependent splice site blockage

Sosnowski, Barbara A.; Belote, John M.; McKeown, Michael

doi:10.1016/0092-8674(89)90426-1

Cited by 272 publications

(186 citation statements)

References 38 publications

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“…For example, the female-specific RNA binding protein SEX-LETHAL (SXL) controls the splicing pattern of the transformer (tra) pre-mRNA by binding to a sequence adjacent to the regulated 3′ splice site, thereby diverting splicing to the female-specific splice site (Granadino et al, 1997;Inoue et al, 1990;Sosnowski et al, 1989;Valcarcel et al, 1993). SXL also suppresses expression of the male-specific-lethal-2 (msl-2) gene by binding similar U-rich sequences (Bashaw and Baker, 1995;Kelley et al, 1995;Zhou et al, 1995).…”

Section: Introductionmentioning

confidence: 99%

Sex-lethalsplicing autoregulation in vivo: interactions between SEX-LETHAL, the U1 snRNP and U2AF underlie male exon skipping

et al. 2003

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Alternative splicing of the Sex-lethal pre-mRNA has long served as a model example of a regulated splicing event, yet the mechanism by which the female-specific SEX-LETHAL RNA-binding protein prevents inclusion of the translationterminating male exon is not understood. Thus far, the only general splicing factor for which there is in vivo evidence for a regulatory role in the pathway leading to male-exon skipping is sans-fille (snf), a protein component of the spliceosomal U1 and U2 snRNPs. Its role, however, has remained enigmatic because of questions about whether SNF acts as part of an intact snRNP or a free protein. We provide evidence that SEX-LETHAL interacts with SANS-FILLE in the context of the U1 snRNP, through the characterization of a point mutation that interferes with both assembly into the U1 snRNP and complex formation with SEX-LETHAL. Moreover, we find that SEX-LETHAL associates with other integral U1 snRNP components, and we provide genetic evidence to support the biological relevance of these physical interactions. Similar genetic and biochemical approaches also link SEX-LETHAL with the heterodimeric splicing factor, U2AF. These studies point specifically to a mechanism by which SEX-LETHAL represses splicing by interacting with these key splicing factors at both ends of the regulated male exon. Moreover, because U2AF and the U1 snRNP are only associated transiently with the pre-mRNA during the course of spliceosome assembly, our studies are difficult to reconcile with the current model that proposes that the SEX-LETHAL blocks splicing at the second catalytic step, and instead argue that the SEX-LETHAL protein acts after splice site recognition, but before catalysis begins.

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Section: Introductionmentioning

confidence: 99%

Sex-lethalsplicing autoregulation in vivo: interactions between SEX-LETHAL, the U1 snRNP and U2AF underlie male exon skipping

et al. 2003

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“…The sex-specific splicing factor Sex-lethal (SXL) regulates the splicing of transformer (tra) pre-mRNA by competing with U2AF 65 for binding to the polypyrimidine tract of the regulated 3Ј splice site. This permits the use of an alternative 3Ј splice site that is normally not selected, thus resulting in the production of a functional TRA protein only in female flies (11)(12)(13)(14)(15)(16). Direct competition with constitutive splicing factors has been shown to be a conserved strategy for vertebrate alternative 3Ј splice site choice and often involves the polypyrimidine tract binding protein (PTB/hnRNP I) (15,(17)(18)(19).…”

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confidence: 99%

Polypyrimidine Track-binding Protein Binding Downstream of Caspase-2 Alternative Exon 9 Represses Its Inclusion

Côté¹,

Dupuis²,

2001

Journal of Biological Chemistry

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We have been using the caspase-2 pre-mRNA as a model system to study the importance of alternative splicing in the regulation of programmed cell death. Inclusion or skipping of a cassette-type exon in the 3 portion of this pre-mRNA leads to the production of isoforms with antagonistic activity in apoptosis. We previously identified a negative regulatory element (In100) located in the intron downstream of alternative exon 9. The upstream portion of this element harbors a decoy 3 acceptor site that engages in nonproductive commitment complex interactions with the 5 splice site of exon 9. This in turn confers a competitive advantage to the exon-skipping splicing pattern. Further characterization of the In100 element reveals a second, functionally distinct, domain located downstream from the decoy 3 acceptor site. This downstream domain harbors several polypyrimidine track-binding protein (PTB)-binding sites. We show that PTB binding to these sites correlates with the negative effect on exon 9 inclusion. Finally, we show that both domains of the In100 element can function independently to repress exon 9 inclusion, although PTB binding in the vicinity of the decoy 3 splice site can modulate its activity. Our results thus reveal a complex composite element that regulates caspase-2 exon 9 alternative splicing through a novel mechanism.Pre-mRNA alternative splicing is an important mechanism for higher eucaryotes to regulate cell type-and developmental stage-specific gene expression. It provides a potential for an extraordinarily high level of diversity in generating multiple, often functionally distinct, protein isoforms from a single gene. In addition to the basic splicing signals (5Ј splice site, branch point sequence and pyrimidine tract-AG), numerous sequence elements have been identified in exons or introns that can influence in various ways the function of the splicing machinery (reviewed in Refs. 1-3). These regulatory elements can, in some cases, mediate their effects in cis, for example, through the formation of stem-loop structures (e.g. Ref. 4), although they will usually interact with trans-acting factors. Such factors often form multicomponent complexes that can contain combinations of known constitutive splicing factors, including hnRNPs, 1 snRNPs, and serine-arginine (SR) proteins as well as novel specific alternative splicing factors (e.g. Refs. 5-7). However, little is known about the precise mechanisms by which these specific complexes interact with and influence the function of the splicing machinery. Similarly, the process of splice site selection in complex pre-mRNAs is still a poorly understood phenomenon (8 -10).One mechanism for intronic elements to function in repressing splicing was first described in Drosophila. The sex-specific splicing factor Sex-lethal (SXL) regulates the splicing of transformer (tra) pre-mRNA by competing with U2AF 65 for binding to the polypyrimidine tract of the regulated 3Ј splice site. This permits the use of an alternative 3Ј splice site that is normally not selected,...

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“…This observation led to the conclusion that tra functioning was limited to somatic cells. In somatic cells, tra seemed to be only a slave to Sxl, continually depending on female-specific SXL-F protein to elicit production of its own feminizing protein product (Nagoshi et al 1988;Sosnowski et al 1989). …”

Section: Iplo-x Somatic Cells Of Drosophila Melanogastermentioning

confidence: 99%

“…The mutant Sxl-f7 protein thereby produced can activate an Sxl 1 allele in trans, but far less effectively than wild-type protein. Furthermore, since SXL-F7 cannot direct female-specific expression of tra (Cline 1984;Sosnowski et al 1989), any feminization of somatic tissues that occurs when Sxl f7,M1 is in the presence of a second Sxl allele must result from the productive splicing of Sxl transcripts from that allele. Although Sxl f7,M1 lacks somatic feminizing activity, its germlinefeminizing functions are intact, as first shown by the observation that the homozygous Sxl f7,M1 germline clones produce functional eggs (Cline 1983a)-another indication of profound differences between germline and somatic sex determination.…”

Section: Iplo-x Somatic Cells Of Drosophila Melanogastermentioning

confidence: 99%

Sexual Back Talk With Evolutionary Implications: Stimulation of the Drosophila Sex-Determination Gene Sex-lethal by Its Target transformer

Siera

Cline

2008

Genetics

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Sex-specific alternative splicing of RNA from the transformer gene results from sequence-dependent splice site blockage

Cited by 272 publications

References 38 publications

Sex-lethalsplicing autoregulation in vivo: interactions between SEX-LETHAL, the U1 snRNP and U2AF underlie male exon skipping

Sex-lethalsplicing autoregulation in vivo: interactions between SEX-LETHAL, the U1 snRNP and U2AF underlie male exon skipping

Polypyrimidine Track-binding Protein Binding Downstream of Caspase-2 Alternative Exon 9 Represses Its Inclusion

Sexual Back Talk With Evolutionary Implications: Stimulation of the Drosophila Sex-Determination Gene Sex-lethal by Its Target transformer

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