U2 snRNP is required for expression of the 3' end of genes.
Pre-mRNA in eukaryotes is subjected to mRNA processing, which includes capping, polyadenylation, and splicing. Transcription and mRNA processing are coupled, and this coupling stimulates mRNA processing; however, the effects of mRNA processing on transcription are not fully understood. In this study, we found that inhibition of U2 snRNP by a splicing inhibitor, spliceostatin A (SSA), or by an antisense oligonucleotide to U2 snRNA, caused gene-specific 3'-end down-regulation. Removal of SSA from the culture media restored expression of the 3' ends of genes, suggesting that U2 snRNP is required for expression of the 3' end of genes. Finally, we found that SSA treatment caused accumulation of Pol II near the 5' end of 3'-end down regulated genes, such as CDK6, SMEK2 and EGFR, indicating that SSA treatment led to transcription elongation arrest on these genes. These findings suggest that U2 snRNP is important for production of full length mRNA probably through regulation of transcription elongation, and that a novel checkpoint mechanism prevents pre-mRNA from accumulating as a result of splicing deficiencies, and thereby prevents production of aberrant proteins that might be translated from pre-mRNAs through the arrest of transcription elongation.
Frontier Research Core for Life Sciences, University of Toyama, Toyama, Japan.
Mitsunori
M
Koga
Frontier Research Core for Life Sciences, University of Toyama, Toyama, Japan.
Takayuki
T
Satoh
Division of Molecular Genetics Research, Life Science Research Center, University of Toyama, Toyama, Japan.
Ichiro
I
Takasaki
Molecular Ligand Target Research Team, RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan.
Yumi
Y
Kawamura
Chemical Genetics Laboratory, RIKEN, Wako, Saitama, Japan; JST, CREST, Kawaguchi, Saitama, Japan.
Minoru
M
Yoshida
Frontier Research Core for Life Sciences, University of Toyama, Toyama, Japan.
Daisuke
D
Kaida
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D002460:Cell Line; D063326:Exosome Multienzyme Ribonuclease Complex / Q000235:genetics; D005786:Gene Expression Regulation / Q000187:drug effects; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D011714:Pyrans / Q000494:pharmacology; D012319:RNA Polymerase II / Q000378:metabolism; D012322:RNA Precursors / Q000235:genetics; D012326:RNA Splicing / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000378:metabolism*; D013141:Spiro Compounds / Q000494:pharmacology; D014158:Transcription, Genetic
D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; C571394:EXOSC2 protein, human; D011714:Pyrans; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D017413:Ribonucleoprotein, U2 Small Nuclear; D013141:Spiro Compounds; C553684:spliceostatin A; D012319:RNA Polymerase II; D063326:Exosome Multienzyme Ribonuclease Complex