Difference in the genomic organizations of the related transcription factors Sp1 and Krox-20; possible evolutionary significance.
We report here part of the genomic sequence of the mouse homolog of the human gene encoding the transcription factor Sp1. This gene belongs to a subfamily of zinc finger proteins, which includes another transcription factor, Krox-20. The analysis of the mouse Sp1 nucleotide sequence revealed that (i) the C-terminal part of the protein is conserved between man and mouse, consistent with a possible role in transcriptional activation; (ii) while the there Krox-20 zinc fingers are encoded by a unique exon, an intron separates the regions encoding fingers 2 and 3 of Sp1. On the basis of this latter observation, we propose a model for the evolution of the Sp1/Krox-20 gene family which might shed some light on the role of introns in the evolution of modular proteins.
Chestier
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Laboratoire de Génétique Moléculaire, CNRS URA 1302, Ecole Normale Supérieure, Paris, France.
Charnay
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D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D004268:DNA-Binding Proteins / Q000235:genetics*; D051767:Early Growth Response Protein 2; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D012689:Sequence Homology, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D016335:Zinc Fingers / Q000235:genetics
D004268:DNA-Binding Proteins; C497326:EGR2 protein, human; D051767:Early Growth Response Protein 2; C497327:Egr2 protein, mouse; D016329:Sp1 Transcription Factor; D014157:Transcription Factors