Abstract
Max, a basic–helix–loop–helix–leucine zipper (bHLH-ZIP) protein, plays a central role in the transcriptional regulation of myc oncoprotein-responsive genes. Myc-max heterodimers bind to consensus E-box motifs near or within the promoters of these genes and activate gene expression, whereas heterodimers between max and members of the mad family of bHLH-ZIP proteins promote transcriptional repression. In contrast to all other members of the myc network, max readily homodimerizes and binds to identical E-box sites in vitro. However, the role for max homodimers in transcriptional repression in vivo is unclear. Upstream stimulatory factor (USF) is a bHLH-ZIP protein which does not interact with members of the myc-max-mad family. By replacing the HLH-ZIP domain of max with that from USF, we created a chimeric protein, max(USF), which was indistinguishable from max with respect to its ability to homodimerize and bind DNA. As expected, however, max(USF) was unable to heterodimerize with any of the tested max partner proteins and was incapable of suppressing c-myc target genes. Thus, transcriptional repression is an exclusive property of max-mad heterodimers and cannot be achieved by max homodimers alone.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 50 print issues and online access
$259.00 per year
only $5.18 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yin, X., Grove, L. & Prochownik, E. Lack of transcriptional repression by max homodimers. Oncogene 16, 2629–2637 (1998). https://doi.org/10.1038/sj.onc.1201777
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/sj.onc.1201777
Keywords
This article is cited by
-
Mlx, a new Max-like bHLHZip family member: the center stage of a novel transcription factors regulatory pathway?
Oncogene (2000)
-
Mmip-2, a novel RING finger protein that interacts with mad members of the Myc oncoprotein network
Oncogene (1999)
-
New Myc-interacting proteins: a second Myc network emerges
Oncogene (1999)