Assignment of the human gene encoding heterogeneous nuclear RNA ribonucleoprotein I (PTB) to chromosome 14q23-q24.1.

Abstract

Heterogeneous nuclear ribonucleoprotein type I (hnRNP I), also known as the polypyrimidine tract binding protein (PTB), is a 59.6-kDa nuclear protein that binds pre-mRNAs in specific regions of the hnRNA-protein complexes, sensitive to micrococcal nuclease. A 15,000-bp genomic clone encompassing part of the PTB cDNA, used as a biotinylated probe in a fluorescence in situ hybridization (FISH) experiment, has shown that the human PTB gene is localized on bands 14q23-q24.1. In the nucleus of eukaryotic cells, nascent heterogeneous nuclear RNAs (hnRNAs) associate with a distinct set of abundant nuclear proteins to form heterogeneous nuclear ribonuclear proteins (hnRNP) complexes. HnRNP complexes immunopurified from HeLa cells are composed of at least 20 major RNA binding proteins, designated A1 (34 kDa) through U (120 kDa). HnRNP complexes are thought to be substrate for transcriptional processing events. 19 refs., 2 figs.