title: A novel polypyrimidine tract-binding protein paralog expressed in smooth muscle cells.
abstract: Polypyrimidine tract-binding protein (PTB) is an abundant widespread RNA-binding protein with roles in regulation of pre-mRNA alternative splicing and 3'-end processing, internal ribosomal entry site-driven translation, and mRNA localization. Tissue-restricted paralogs of PTB have previously been reported in neuronal and hematopoietic cells. These proteins are thought to replace many general functions of PTB, but to have some distinct activities, e.g. in the tissue-specific regulation of some alternative splicing events. We report the identification and characterization of a fourth rodent PTB paralog (smPTB) that is expressed at high levels in a number of smooth muscle tissues. Recombinant smPTB localized to the nucleus, bound to RNA, and was able to regulate alternative splicing. We suggest that replacement of PTB by smPTB might be important in controlling some pre-mRNA alternative splicing events.
authors.affiliation: Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, United Kingdom.
authors.forename: Clare
authors.initials: C
authors.lastname: Gooding
authors.forename: Paul
authors.initials: P
authors.lastname: Kemp
authors.forename: Christopher W J
authors.initials: CW
authors.lastname: Smith
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D001011:Aorta; D001483:Base Sequence; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000737:chemistry* / Q000378:metabolism; D038941:Polypyrimidine Tract-Binding Protein / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D012322:RNA Precursors / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D051381:Rats; D016415:Sequence Alignment; D017385:Sequence Homology; D014018:Tissue Distribution
chemical_list: D034441:Heterogeneous-Nuclear Ribonucleoproteins; D009124:Muscle Proteins; C475523:Ptbp1 protein, rat; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D038941:Polypyrimidine Tract-Binding Protein