Related Experiment Video
Updated: May 15, 2026

ACT1-CUP1 Assays Determine the Substrate-Specific Sensitivities of Spliceosomal Mutants in Budding Yeast
Published on: June 30, 2022
Structure of phosphorylated SF1 bound to U2AF⁶⁵ in an essential splicing factor complex
Wenhua Wang1, Alexandre Maucuer, Ankit Gupta
1Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA.
Abstract:
The essential splicing factors U2AF⁶⁵ and SF1 cooperatively bind consensus sequences at the 3' end of introns. Phosphorylation of SF1 on a highly conserved "SPSP" motif enhances its interaction with U2AF⁶⁵ and the pre-mRNA. Here, we reveal that phosphorylation induces essential conformational changes in SF1 and in the SF1/U2AF⁶⁵/3' splice site complex. Crystal structures of the phosphorylated (P)SF1 domain bound to the C-terminal domain of U2AF⁶⁵ at 2.29 Å resolution and of the unphosphorylated SF1 domain at 2.48 Å resolution demonstrate that phosphorylation induces a disorder-to-order transition within a previously unknown SF1/U2AF⁶⁵ interface. We find by small-angle X-ray scattering that the local folding of the SPSP motif transduces into global conformational changes in the nearly full-length (P)SF1/U2AF⁶⁵/3' splice site assembly. We further determine that SPSP phosphorylation and the SF1/U2AF⁶⁵ interface are essential in vivo. These results offer a structural prototype for phosphorylation-dependent control of pre-mRNA splicing factors.
Related Concept Videos
RNA Splicing
RNA Splicing
Protein Complexes with Interchangeable Parts
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Pre-mRNA Processing: RNA Splicing
RNA Polymerase II Accessory Proteins
RNA Polymerase II Accessory Proteins

