The human high mobility group (HMG)-box transcription factor TCF-1: novel isoforms due to alternative splicing and usage of a new exon IXA

Biochim Biophys Acta. 1995 Aug 22;1263(2):169-72. doi: 10.1016/0167-4781(95)00108-s.


The C-terminal peptide sequences of the human lymphocyte-specific high mobility group (HMG)-box transcription factor TCF-1 are determined by alternative splice mechanisms affecting the exons VIII to X. Here we report, in addition to four splice forms described previously (TCF-1A, B, C, D), the identification of three novel transcripts designated TCF-1E, F, G. Cloning and sequencing of the novel cDNAs revealed (i) joining of the exons VIII and IX to an internal exon X splice acceptor site resulting in a new open reading frame (ORF) of 99 amino acids derived from exon X sequences, (ii) the identification of an additional functional splice acceptor site within exon X, and (iii) a new 81-nucleotide insertion between exon VIII and exon X sequences in a novel transcript form. Genomic cloning and sequence analysis of this transcribed segment of 81 basepairs revealed that it was bordered by canonical splice consensus sites and located in a distance of some 400 bp from both the exons IX and X. It was therefore termed exon IXA. Novel ORFs were generated as a consequence of these alternative splice mechanisms resulting in TCF-1 gene products with significantly different C-terminal peptide sequences, which are prone to selective protein-protein interactions or transactivating functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing*
  • Amino Acid Sequence
  • Base Sequence
  • DNA, Complementary / analysis
  • DNA, Complementary / isolation & purification
  • DNA-Binding Proteins / genetics*
  • Exons*
  • High Mobility Group Proteins / genetics*
  • Humans
  • Lymphoid Enhancer-Binding Factor 1
  • Molecular Sequence Data
  • Polymerase Chain Reaction
  • RNA, Messenger / analysis
  • T Cell Transcription Factor 1
  • Transcription Factors / genetics*
  • Tumor Cells, Cultured


  • DNA, Complementary
  • DNA-Binding Proteins
  • High Mobility Group Proteins
  • Lymphoid Enhancer-Binding Factor 1
  • RNA, Messenger
  • T Cell Transcription Factor 1
  • TCF7 protein, human
  • Transcription Factors

Associated data

  • GENBANK/Z47361
  • GENBANK/Z47362
  • GENBANK/Z47363
  • GENBANK/Z47364
  • GENBANK/Z47365