A region to the N-terminal side of the CTCF zinc finger domain is essential for activating transcription from the amyloid precursor protein promoter.
Transcription from the amyloid precursor protein (APP) promoter is largely dependent on a nuclear factor binding site designated as APBbeta. The protein that binds to this site is the multifunctional transcription factor CTCF, which consists of 727 amino acids and contains a domain of 11 zinc finger motifs that is flanked by 267 amino acids on the N-terminal side and 150 amino acids on the C-terminal side. Depleting HeLa cell nuclear extract of endogenous CTCF specifically reduced transcriptional activity from the APP promoter. However, transcriptional activity was restored by replenishing the depleted extract with recombinant CTCF. Deleting 201 amino acids from the C-terminal end of CTCF had no detrimental effect on transcriptional activation, whereas deleting either 248 or 284 amino acids from the N-terminal end abolished transcriptional activation. Competing endogenous CTCF in vivo was accomplished by cotransfecting COS-1 cells with a plasmid overexpressing CTCF constructs and a reporter plasmid containing the APP promoter. Under these conditions, an N-terminal deletion of CTCF reduced expression from the APP promoter, whereas the C-terminal deletion had no effect. These results demonstrate that CTCF activates transcription from the APP promoter and that the activation domain is located on the N-terminal side of the zinc finger domain.
Vostrov
Alexander A
AA
Department of Psychiatry and Behavioral Science, State University of New York, Stony Brook, New York 11794-8101, USA.
Taheny
Michael J
MJ
Quitschke
Wolfgang W
WW
D021581:Active Transport, Cell Nucleus; D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D000076246:CCCTC-Binding Factor; D019556:COS Cells; D002458:Cell Fractionation; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D007202:Indicators and Reagents / Q000378:metabolism; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D010843:Pichia / Q000235:genetics / Q000502:physiology; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000378:metabolism; D012097:Repressor Proteins; D017384:Sequence Deletion; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*; D015533:Transcriptional Activation; D016335:Zinc Fingers
D016564:Amyloid beta-Protein Precursor; D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; D004268:DNA-Binding Proteins; D007202:Indicators and Reagents; D008164:Luminescent Proteins; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D049452:Green Fluorescent Proteins