The ability of POU family transcription factors to activate or repress gene expression is dependent on the spacing and context of their specific response elements.
The different forms of the Oct-2 and Brn-3 POU family transcription factors can have distinct effects on their target promoters involving both the activation and repression of gene expression. To investigate the requirements for these effects we have altered both the context and spacing of the two TAATGARAT binding sites for these factors within the herpes simplex virus immediate-early 3 gene promoter. We show that the activation of this promoter by Brn-3a and its repression by Brn-3b is dependent on the correct spacing of these binding sites. In contrast, repression of the promoter by Oct-2.4 and Oct-2.5 is dependent on both the spacing and context of these sites with the requirements for repression by Oct-2.4 or Oct-2.5 being different. These effects are discussed in the context of the mechanisms by which POU factors activate or repress their target genes.
Dawson
S J
SJ
Medical Molecular Biology Unit, Department of Molecular Pathology, University College London Medical School, U.K.
Liu
Y Z
YZ
Rodel
B
B
Möröy
T
T
Latchman
D S
DS
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D006224:Cricetinae; D015342:DNA Probes; D004268:DNA-Binding Proteins; D005786:Gene Expression Regulation; D018398:Homeodomain Proteins; D008969:Molecular Sequence Data; D050809:POU Domain Factors; D014157:Transcription Factors / Q000378:metabolism*
D015342:DNA Probes; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; D050809:POU Domain Factors; D014157:Transcription Factors; C085076:transcription factor Brn-2