A Drosophila RNA polymerase II transcription factor binds to the regulatory site of an hsp 70 gene.
A Drosophila RNA polymerase II transcription factor that is specific for at least one of the heat-shock genes has been isolated (designated HSTF for heat-shock transcription factor). This factor is required for active transcription of an hsp 70 gene in addition to RNA polymerase II and another general transcription factor, the A factor. Footprint analysis of the HSTF on the hsp 70 gene reveals that it binds specifically to a 55 bp region upstream from the TATA box. Both coding and noncoding DNA strands are completely protected from DNAase I cleavage by the HSTF . HSTF binding occurs in the apparent absence of RNA polymerase II. The HSTF is present in both heat-shocked and nonshocked cells, although it is more transcriptionally active when isolated from heat-shocked cells. The previously described B factor (an RNA polymerase II transcription factor that binds to the TATA box), isolated from nonshocked cells, is significantly reduced in both binding and transcriptional activity in heat-shocked cells. The potential role of the HSTF and the B factor in the activation of heat-shock gene transcription is discussed.
D000199:Actins / Q000235:genetics / Q000302:isolation & purification; D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism; D004330:Drosophila / Q000201:enzymology / Q000235:genetics*; D005796:Genes; D005809:Genes, Regulator; D006360:Heat-Shock Proteins / Q000235:genetics* / Q000302:isolation & purification; D007700:Kinetics; D008970:Molecular Weight; D011485:Protein Binding; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*; D014158:Transcription, Genetic
D000199:Actins; D006360:Heat-Shock Proteins; D014157:Transcription Factors