Structure-guided U2AF65 variant improves recognition and splicing of a defective pre-mRNA.Agrawal, A.A., McLaughlin, K.J., Jenkins, J.L., Kielkopf, C.L.
(2014) Proc Natl Acad Sci U S A 111: 17420-17425
- PubMed: 25422459
- DOI: https://doi.org/10.1073/pnas.1412743111
- Primary Citation of Related Structures:
4TU7, 4TU8, 4TU9
- PubMed Abstract:
Purine interruptions of polypyrimidine (Py) tract splice site signals contribute to human genetic diseases. The essential splicing factor U2AF(65) normally recognizes a Py tract consensus sequence preceding the major class of 3' splice sites. We found that neurofibromatosis- or retinitis pigmentosa-causing mutations in the 5' regions of Py tracts severely reduce U2AF(65) affinity. Conversely, we identified a preferred binding site of U2AF(65) for purine substitutions in the 3' regions of Py tracts. Based on a comparison of new U2AF(65) structures bound to either A- or G-containing Py tracts with previously identified pyrimidine-containing structures, we expected to find that a D231V amino acid change in U2AF(65) would specify U over other nucleotides. We found that the crystal structure of the U2AF(65)-D231V variant confirms favorable packing between the engineered valine and a target uracil base. The D231V amino acid change restores U2AF(65) affinity for two mutated splice sites that cause human genetic diseases and successfully promotes splicing of a defective retinitis pigmentosa-causing transcript. We conclude that reduced U2AF(65) binding is a molecular consequence of disease-relevant mutations, and that a structure-guided U2AF(65) variant is capable of manipulating gene expression in eukaryotic cells.
Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642.