Structural basis of CBP/p300 recruitment by the microphthalmia-associated transcription factor

Brown, A. D., Vergunst, K. L., Branch, M., Blair, C. M., Dupré, D. J., Baillie, G. S. and Langelaan, D. N. (2023) Structural basis of CBP/p300 recruitment by the microphthalmia-associated transcription factor. Biochimica et Biophysica Acta: Molecular Cell Research, (doi: 10.1016/j.bbamcr.2023.119520) (PMID:37353163) (In Press)

Abstract

The microphthalmia-associated transcription factor (MITF) is a master regulator of the melanocyte cell lineage. Aberrant MITF activity can lead to multiple malignancies including skin cancer, where it modulates the progression and invasiveness of melanoma. MITF-regulated gene expression requires recruitment of the transcriptional co-regulator CBP/p300, but details of this process are not fully defined. In this study, we investigate the structural and functional interaction between the MITF N-terminal transactivation domain (MITFTAD) and CBP/p300. Using pulldown assays and nuclear magnetic resonance spectroscopy we determined that MITFTAD is intrinsically disordered and binds to the TAZ1 and TAZ2 domains of CBP/p300 with moderate affinity. The solution-state structure of the MITFTAD:TAZ2 complex reveals that MITF interacts with a hydrophobic surface of TAZ2, while remaining somewhat dynamic. Peptide array and mutagenesis experiments determined that an acidic motif is integral to the MITFTAD:TAZ2 interaction and is necessary for transcriptional activity of MITF. Peptides that bind to the same surface of TAZ2 as MITFTAD, such as the adenoviral protein E1A, are capable of displacing MITF from TAZ2 and inhibiting transactivation. These findings provide insight into co-activator recruitment by MITF that are fundamental to our understanding of MITF targeted gene regulation and melanoma biology.

• Item Type: Articles
• Additional Information: FUNDING: This study was funded by a BHCRI New Investigator Grant and a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada (RGPIN-2017-05338). A.B. is supported by the Killam Foundation and a CIHR-CGSD award. K.V. is funded through the Killam Foundation and an NSERC-CGSD award.
• Status: In Press
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Blair, Dr Connor and Baillie, Professor George

Creator Roles

Blair, C. M.: Formal analysis, Investigation, Visualization
Baillie, G. S.: Resources, Supervision

• Authors: Brown, A. D., Vergunst, K. L., Branch, M., Blair, C. M., Dupré, D. J., Baillie, G. S., and Langelaan, D. N.
• College/School: College of Medical Veterinary and Life Sciences > School of Cardiovascular & Metabolic Health
• Journal Name: Biochimica et Biophysica Acta: Molecular Cell Research
• Publisher: Elsevier
• ISSN: 0167-4889
• ISSN (Online): 1879-2596
• Published Online: 21 June 2023
• Copyright Holders: Copyright © 2023 Published by Elsevier B.V
• First Published: First published in Biochimica et Biophysica Acta: Molecular Cell Research 2023
• Publisher Policy: Reproduced in accordance with the publisher copyright policy