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U2 AF 65 assemblies drive sequence‐specific splice site recognition
Author(s) -
Tari Manel,
Manceau Valérie,
Matha Salone Jean,
Kobayashi Asaki,
Pastré David,
Maucuer Alexandre
Publication year - 2019
Publication title -
embo reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.584
H-Index - 184
eISSN - 1469-3178
pISSN - 1469-221X
DOI - 10.15252/embr.201847604
Subject(s) - snrnp , rna splicing , splice , rna binding protein , splicing factor , exon , rna , ribonucleoprotein , biology , linker , microbiology and biotechnology , genetics , gene , computer science , operating system
The essential splicing factor U2 AF 65 is known to help anchoring U2 snRNP at the branch site. Its C‐terminal UHM domain interacts with ULM motifs of SF 3b155, an U2 snRNP protein. Here, we report a cooperative binding of U2 AF 65 and the related protein CAPER α to the multi‐ ULM domain of SF 3b155. In addition, we show that the RS domain of U2 AF 65 drives a liquid–liquid phase separation that is amplified by intronic RNA with repeated pyrimidine tracts. In cells, knockdown of either U2 AF 65 or CAPER α improves the inclusion of cassette exons that are preceded by such repeated pyrimidine‐rich motifs. These results support a model in which liquid‐like assemblies of U2 AF 65 and CAPER α on repetitive pyrimidine‐rich RNA sequences are driven by their RS domains, and facilitate the recruitment of the multi‐ ULM domain of SF 3b155. We anticipate that posttranslational modifications and proteins recruited in dynamical U2 AF 65 and CAPER α condensates may further contribute to the complex mechanisms leading to specific splice site choice that occurs in cells.