title: Attenuated function of a variant form of the helix-loop-helix protein, Id-3, generated by an alternative splicing mechanism.
abstract: The Id family of helix-loop-helix proteins function as negative regulators of DNA binding, basic helix-loop-helix proteins in the regulation of cell growth and differentiation. We report here on the identification of a 17 kDa variant of the 14 kDa Id-3 protein termed Id-3L (long version) which possesses a unique 60 amino acid carboxy-terminus generated by read through of a 'coding intron' and alternative splicing. Northern analysis revealed expression of a minor 1.1 kb Id-3L transcript together with the predominant 0.95 kb Id-3 transcript in the majority of adult human tissues analysed. The variant Id-3L protein is functionally distinguishable from conventional Id-3 since in in vitro DNA mobility shift assays, it was greatly impaired in its ability to abrogate binding of the basic helix-loop-helix protein, E47, to an E box recognition sequence.
authors.affiliation: CRC Department of Gene Regulation, Paterson Institute for Cancer Research, Christie Hospital NHS Trust, UK. grgrwd@picr.cr.man.ac.uk
authors.forename: R W
authors.initials: RW
authors.lastname: Deed
authors.forename: M
authors.initials: M
authors.lastname: Jasiok
authors.forename: J D
authors.initials: JD
authors.lastname: Norton
mesh_terms: D000328:Adult; D017398:Alternative Splicing; D001402:B-Lymphocytes / Q000166:cytology; D015152:Blotting, Northern; D002478:Cells, Cultured; D015870:Gene Expression; D014644:Genetic Variation; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D051796:Inhibitor of Differentiation Proteins; D009363:Neoplasm Proteins; D012313:RNA / Q000032:analysis; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
chemical_list: D051796:Inhibitor of Differentiation Proteins; D009363:Neoplasm Proteins; D014157:Transcription Factors; C075640:ID3 protein, human; D012313:RNA