ATM and ATR pathways signal alternative splicing of Drosophila TAF1 pre-mRNA in response to DNA damage.
Alternative pre-mRNA splicing is a major mechanism utilized by eukaryotic organisms to expand their protein-coding capacity. To examine the role of cell signaling in regulating alternative splicing, we analyzed the splicing of the Drosophila melanogaster TAF1 pre-mRNA. TAF1 encodes a subunit of TFIID, which is broadly required for RNA polymerase II transcription. We demonstrate that TAF1 alternative splicing generates four mRNAs, TAF1-1, TAF1-2, TAF1-3, and TAF1-4, of which TAF1-2 and TAF1-4 encode proteins that directly bind DNA through AT hooks. TAF1 alternative splicing was regulated in a tissue-specific manner and in response to DNA damage induced by ionizing radiation or camptothecin. Pharmacological inhibitors and RNA interference were used to demonstrate that ionizing-radiation-induced upregulation of TAF1-3 and TAF1-4 splicing in S2 cells was mediated by the ATM (ataxia-telangiectasia mutated) DNA damage response kinase and checkpoint kinase 2 (CHK2), a known ATM substrate. Similarly, camptothecin-induced upregulation of TAF1-3 and TAF1-4 splicing was mediated by ATR (ATM-RAD3 related) and CHK1. These findings suggest that inducible TAF1 alternative splicing is a mechanism to regulate transcription in response to developmental or DNA damage signals and provide the first evidence that the ATM/CHK2 and ATR/CHK1 signaling pathways control gene expression by regulating alternative splicing.
Katzenberger
Rebeccah J
RJ
University of Wisconsin School of Medicine and Public Health, Department of Pharmacology, Madison, WI 53706, USA.
Marengo
Matthew S
MS
Wassarman
David A
DA
D017398:Alternative Splicing / Q000502:physiology*; D000595:Amino Acid Sequence; D000818:Animals; D064007:Ataxia Telangiectasia Mutated Proteins; D018797:Cell Cycle Proteins / Q000502:physiology*; D002460:Cell Line; D004249:DNA Damage / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000502:physiology*; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D051548:Histone Acetyltransferases / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000502:physiology*; D012322:RNA Precursors / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID / Q000096:biosynthesis / Q000235:genetics*; D025521:Tumor Suppressor Proteins / Q000502:physiology*
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D020033:Protein Isoforms; D012322:RNA Precursors; D035381:TATA-Binding Protein Associated Factors; D035362:Transcription Factor TFIID; D025521:Tumor Suppressor Proteins; D051548:Histone Acetyltransferases; D064007:Ataxia Telangiectasia Mutated Proteins; C444435:Mei-41 protein, Drosophila; D017346:Protein Serine-Threonine Kinases; C069001:TATA-binding protein associated factor 250 kDa