A Splicing Repressor Domain in Polypyrimidine Tract-binding Protein

Fiona Robinson, Christopher W. J. Smith
2005 Journal of Biological Chemistry  
Polypyrimidine tract-binding protein (PTB) is an hnRNP with four RRM type domains. It plays roles as a repressive alternative splicing regulator of multilple target genes, as well as being involved in pre-mRNA 3 end processing, mRNA localization, stability, and internal ribosome entry site-mediated translation. Here we have used a tethered function assay, in which a fusion protein of PTB and the bacteriophage MS2 coat protein is recruited to a splicing regulatory site by binding to an
more » ... ing to an artificially inserted MS2 binding site. Deletion mutations of PTB in this system allowed us to identify RRM2 and the following inter-RRM linker region as the minimal region of PTB that can act as splicing repressor domain when recruited to RNA. Splicing repression by the minimal repressor domain remained cell type-specific and dependent upon other defined regulatory elements in the ␣-tropomyosin test minigene. Our results highlight the fact that splicing repression by PTB can be uncoupled from the mode by which it binds to RNA.
doi:10.1074/jbc.m510578200 pmid:16282332 fatcat:6dnup4hqzrc6himbpsbzlsq7xm