HSP90 Stabilizes Auxin-Responsive Phenotypes by Masking a Mutation in the Auxin Receptor TIR1.

Publisher: Oxford University Press Country of Publication: Japan NLM ID: 9430925 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1471-9053 (Electronic) Linking ISSN: 00320781 NLM ISO Abbreviation: Plant Cell Physiol Subsets: MEDLINE

Publication: Tokyo : Oxford University Press
Original Publication: Kyoto, Japan : Japanese Society of Plant Physiologists,

Arabidopsis/*genetics ; Arabidopsis/*metabolism ; Arabidopsis Proteins/*genetics ; Arabidopsis Proteins/*metabolism ; F-Box Proteins/*genetics ; HSP90 Heat-Shock Proteins/*metabolism ; Indoleacetic Acids/*pharmacology ; Mutation/*genetics ; Receptors, Cell Surface/*genetics; Arabidopsis/growth & development ; Cell Nucleus/drug effects ; Cell Nucleus/metabolism ; Cytosol/metabolism ; F-Box Proteins/metabolism ; Gene Expression Regulation, Plant/drug effects ; Genes, Plant ; Phenotype ; Protein Binding/drug effects ; Proteolysis/drug effects ; Receptors, Cell Surface/metabolism ; Transcription Factors/metabolism

Heat shock protein 90 (HSP90) is a molecular chaperone that is required for the function of various substrate proteins, also known as client proteins. It is proposed that HSP90 buffers or hides phenotypic variations in animals and plants by masking mutations in some of its client proteins. However, none of the client proteins with cryptic mutations has been identified to date. Here, we identify the first client protein example by which HSP90 buffers a mutation: the auxin receptor transport inhibitor response 1 (TIR1). TIR1 interacts with HSP90 in the nucleus. An HSP90-specific inhibitor abolished the nuclear localization of TIR1 and the auxin-induced degradation of a TIR1-substrate, indicating that TIR1 is an HSP90 client protein. Plants with a null mutation in the TIR1 gene had a defect in auxin response, whereas plants with a point mutation in the TIR1 gene responded to auxin treatment in young seedlings, but a cryptic defect in its auxin response was exposed with HSP90 inhibitor treatment. These results demonstrate that HSP90 masks a point mutation in the auxin receptor TIR1 and thereby buffers auxin-responsive phenotypes.
(© The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Keywords: Auxin receptor; Buffering; HSP90; Phenotypic variation; TIR1

0 (Arabidopsis Proteins)
0 (F-Box Proteins)
0 (HSP90 Heat-Shock Proteins)
0 (Hsp90-1 protein, Arabidopsis)
0 (IAA7 protein, Arabidopsis)
0 (Indoleacetic Acids)
0 (Receptors, Cell Surface)
0 (TIR1 protein, Arabidopsis)
0 (Transcription Factors)

Date Created: 20161107 Date Completed: 20170327 Latest Revision: 20170327

20250114

10.1093/pcp/pcw170

27816945