THE GENE FOR THE HUMAN ARCHITECTURAL TRANSCRIPTION FACTOR HMGI-C CONSISTS OF 5 EXONS EACH CODING FOR A DISTINCT FUNCTIONAL ELEMENT

The gene on chromosome 12 coding for the human protein HMGI-C has been cloned and partially sequenced, It consists of five exons, the first and last of which include long untranslated regions, The 5' UTR includes a (CA/T)(n) tract and a polymorphic (CT)(n) tract, Exons II, III and IV (87, 51 and 33 bp) are dispersed over >30 kb, Exons I-III separately encode the three basic DNA binding domains ('A-T hooks'), exon IV encodes an 11 amino acid sequence characteristic of HMGI-C and absent from the human HMGI(Y) gene [Friedmann,M., Holth, L.T., Zoghbi,H,Y, and Reeves,R, (1993) Nucleic Acids Res., 21, 4259-4267], whilst exon V encodes the acidic C-terminal domain, which is subject to multiple phosphorylation, The HMGI-C gene is thus a striking example of the separation of functional protein elements into different coding exons.