Intron removal requires proofreading of U2AF/3' splice site recognition by DEK.
Discrimination between splice sites and similar, nonsplice sequences is essential for correct intron removal and messenger RNA formation in eukaryotes. The 65- and 35-kD subunits of the splicing factor U2AF, U2AF65 and U2AF35, recognize, respectively, the pyrimidine-rich tract and the conserved terminal AG present at metazoan 3' splice sites. We report that DEK, a chromatin- and RNA-associated protein mutated or overexpressed in certain cancers, enforces 3' splice site discrimination by U2AF. DEK phosphorylated at serines 19 and 32 associates with U2AF35, facilitates the U2AF35-AG interaction and prevents binding of U2AF65 to pyrimidine tracts not followed by AG. DEK and its phosphorylation are required for intron removal, but not for splicing complex assembly, which indicates that proofreading of early 3' splice site recognition influences catalytic activation of the spliceosome.
Soares
Luis Miguel Mendes
LM
Centre de Regulació Genòmica, Passeig Marítim 37-49, 08003 Barcelona, Spain.
Zanier
Katia
K
Mackereth
Cameron
C
Sattler
Michael
M
Valcárcel
Juan
J
D000255:Adenosine Triphosphate / Q000378:metabolism; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D019281:Dimerization; D015226:Dinucleoside Phosphates / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007438:Introns; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism*; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D000075223:Poly-ADP-Ribose Binding Proteins; D011743:Pyrimidines / Q000378:metabolism; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D017413:Ribonucleoprotein, U2 Small Nuclear; D012261:Ribonucleoproteins / Q000378:metabolism*; D017381:Spliceosomes / Q000378:metabolism; D000072668:Splicing Factor U2AF
D002868:Chromosomal Proteins, Non-Histone; C084738:DEK protein, human; D015226:Dinucleoside Phosphates; D009687:Nuclear Proteins; D015513:Oncogene Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D011743:Pyrimidines; D012322:RNA Precursors; D012333:RNA, Messenger; D011994:Recombinant Proteins; D017413:Ribonucleoprotein, U2 Small Nuclear; D012261:Ribonucleoproteins; D000072668:Splicing Factor U2AF; C076753:U2AF1 protein, human; C000607494:U2AF2 protein, human; D000255:Adenosine Triphosphate