Mapping functional regions of the segment-specific transcription factor Krox-20

• Published in: Nucleic acids research 1992-05, Vol.20 (10), p.2485-2492
• Main Authors: Vesque, C, Charnay, P
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Base Sequence; Blotting, Western; Cell Line; DNA - metabolism; DNA Mutational Analysis; DNA-Binding Proteins - chemistry; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Early Growth Response Protein 2; Escherichia coli - genetics; Fluorescent Antibody Technique; Molecular Sequence Data; Recombinant Fusion Proteins - genetics; Structure-Activity Relationship; Transcription Factors - chemistry; Transcription Factors - genetics; Transcription Factors - metabolism; Transcription, Genetic - genetics; Zinc Fingers - genetics
• ISSN: 0305-1048; 1362-4962
• DOI: 10.1093/nar/20.10.2485

Krox-20, a zinc finger transcription factor with similarity to Sp1, is likely to play an important role in the development of the vertebrate central nervous system. A knowledge of its molecular properties will help to understand its physiological functions. We have therefore performed a structure-function analysis of the protein to identify the regions involved in DNA-binding and transcriptional activation. Our data suggest that only the zinc fingers are required for high affinity, specific DNA-binding. Transcriptional activation was not affected by deletion of the C-terminal tail of the protein. In contrast, deletion of the N-terminal half, upstream of the zinc fingers, completely abolished transactivation without affecting DNA-binding or nuclear localization. Two transcriptional activation domains were identified in this region. They cooperate to establish full activity. They are rich in negatively-charged amino acids and are therefore may constitute acidic activation domains. Comparative analysis of the amino acid sequences of several zinc finger proteins belonging to the Krox-20 subfamily indicates that they contain acidic regions at similar locations within their N-terminal region, suggesting that the functional organization of these proteins has been conserved during evolution.