Identification and Characterization of a Minimal Functional Splicing Regulatory Protein, PTBP1

• DOI: 10.1021/acs.biochem.0c00664
• Publication Date: 2020-12-08T22:55:25Z
• Authors: Robert J. Ontiveros; Luis Hernandez; Haylena Nguyen; Adrian Lino Herna...; Archana Shankar; Enoch Kim; Niroshika M. Kepp...
• Keywords: Polypyrimidine tract-binding protein; Exonic splicing enhancer; Heterogeneous ribonucleoprotein particle; Small nucleolar RNA

Polypyrimidine tract binding protein 1 (PTBP1) is a well-studied RNA that serves as an important model for understanding molecular mechanisms underlying alternative splicing regulation. PTBP1 has four domains (RBDs) connected via linker regions. Additionally, N-terminal unstructured region contains nuclear import and export sequences. Each RBD can bind to pyrimidine rich elements with high affinity mediate activity. Studies support variety of models how regulation on target exons. Obtaining detailed atomic view hinges determining crystal structure bound transcript. Here, we created minimal functional deletions in both 2 regions assayed activity certain regulated exons, including the c-Src N1 exon. We show subset PTBP1-regulated exons are not necessary repression Gel mobility shift assays reveal deletion mutant binds 12-fold higher sequence compared wild-type PTBP1. A also than Moreover, this oligomerizes readily form distinct higher-order complex previously shown be required mediating repression. This serve candidate future studies understand mechanism