Logo image
A naturally occuring insertion of a single amino acid rewires transcriptional regulation by glucocorticoid receptor isoforms
Journal article   Open access   Peer reviewed

A naturally occuring insertion of a single amino acid rewires transcriptional regulation by glucocorticoid receptor isoforms

Morgane Thomas-Chollier, Lisa C Watson, Samantha B Cooper, Miles A Pufall, Jennifer S Liu, Katja Borzym, Martin Vingron, Keith R Yamamoto and Sebastiaan H Meijsing
Proceedings of the National Academy of Sciences - PNAS, Vol.110(44), pp.17826-17831
10/29/2013
DOI: 10.1073/pnas.1316235110
PMCID: PMC3816441
PMID: 24127590
url
https://doi.org/10.1073/pnas.1316235110View
Published (Version of record) Open Access

Abstract

For proteins to be able to have context-specific activities, they can adopt context-specific conformations that enhance or restrict their activity. For transcriptional regulatory factors, such a context-specific signal is provided by the sequence of the DNA response element to which it binds. Here we show how one signal, an alternative splicing event, rewires a transcriptional regulatory protein to respond differently to a second signal, the DNA sequence to which it binds, by changing the functional interplay between protein domains. Together, our findings argue that bidirectional allosteric signaling between the DNA:protein interface and other regulatory domains fine tunes the activity of transcriptional regulatory factors toward individual target genes. In addition to guiding proteins to defined genomic loci, DNA can act as an allosteric ligand that influences protein structure and activity. Here we compared genome-wide binding, transcriptional regulation, and, using NMR, the conformation of two glucocorticoid receptor (GR) isoforms that differ by a single amino acid insertion in the lever arm, a domain that adopts DNA sequence-specific conformations. We show that these isoforms differentially regulate gene expression levels through two mechanisms: differential DNA binding and altered communication between GR domains. Our studies suggest a versatile role for DNA in both modulating GR activity and also in directing the use of GR isoforms. We propose that the lever arm is a ”fulcrum” for bidirectional allosteric signaling, conferring conformational changes in the DNA reading head that influence DNA sequence selectivity, as well as conferring changes in the dimerization domain that connect functionally with remote regulatory surfaces, thereby influencing which genes are regulated and the magnitude of their regulation.
Biological Sciences steroid hormone receptor sequence motifs alternative splicing

Details

Metrics

Logo image