Binding and activation of the promoter for the neural cell adhesion molecule by Pax-8.
The neural cell adhesion molecule (N-CAM), is expressed in definite spatiotemporal patterns during development. To identify factors that may influence place-dependent n-cam gene expression, we have studied the binding and activation of the n-cam promoter by Pax-8, a member of the Pax family of transcription factors. Pax-8 increased n-cam promoter activity 13.4-fold in cellular co-transfection experiments, and a short segment of the promoter (-143 to -15) mediated the response. This region of the n-cam promoter produced a DNA-protein complex when incubated with either extracts from COS-7 cells transfected with the Pax-8 expression vector or a Pax-8/GST fusion protein. Pax-8 bound to the n-cam promoter through two TGCTCC motifs (designated PBS-1 and PBS-2) that resemble paired domain binding sites. Mutation of PBS-1 and PBS-2 eliminated Pax-8 activation of the n-cam promoter. Transfection of N2A neuroblastoma cells with the Pax-8 expression vector resulted in a 5-fold increase in the transcription of the endogenous n-cam gene. The combined results suggest that Pax-8 activates transcription of the n-cam gene through binding of sequences resembling paired domain binding sites in the n-cam promoter. The data raise the possibility that the n-cam promoter may be regulated by other members of the Pax gene family.
Holst
B D
BD
Department of Neurobiology, Scripps Research Institute, La Jolla, California 92037.
Goomer
R S
RS
Wood
I C
IC
Edelman
G M
GM
Jones
F S
FS
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics* / Q000378:metabolism; D004247:DNA; D004268:DNA-Binding Proteins / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D015534:Trans-Activators / Q000378:metabolism*
D015816:Cell Adhesion Molecules, Neuronal; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors; C499496:Pax8 protein, mouse; D015534:Trans-Activators; D004247:DNA