Dataset Information

Degron flexibility enforces auxin sensing

ABSTRACT: Cullin RING-type E3 ubiquitin ligase SCFTIR1/AFB1-5 and their ubiquitylation targets, AUX/IAAs, sense auxin concentrations in the nucleus. TIR1 binds a surface- exposed degron in AUX/IAAs promoting their ubiquitylation and rapid auxin-regulated proteasomal degradation. Here, we resolved TIR1·auxin·IAA7 and TIR1·auxin·IAA12 complex topology, and show that flexible intrinsically disordered regions (IDRs) cooperatively position AUX/IAAs on TIR1. The AUX/IAA PB1 interaction domain also assists in non-native contacts, affecting AUX/IAA dynamic interaction states. Our results establish a role for IDRs in modulating auxin receptor assemblies. By securing AUX/IAAs on two opposite surfaces of TIR1, IDR diversity supports locally tailored positioning for targeted ubiquitylation, and might provide conformational flexibility for adopting a multiplicity of functional states. We postulate IDRs in distinct members of the AUX/IAA family to be an adaptive signature for protein interaction and initiation region for proteasome recruitment.

INSTRUMENT(S): Q Exactive Plus

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Plant Cell, Seedling

DISEASE(S): Disease Free

SUBMITTER: Wolfgang Hoehenwarter

LAB HEAD: Wolfgang Hoehenwarter

PROVIDER: PXD015392 | Pride | 2020-05-27

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	MIN110618-12-IAA.mgf	Mgf
	MIN110618-12-IAA.mzid.gz	Mzid
	MIN110618-12-IAA.pride.mgf.gz	Mgf
	MIN110618-12-IAA.pride.mztab.gz	Mztab
	MIN110618-12-IAA.raw	Raw

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Publications

Flexibility of intrinsically disordered degrons in AUX/IAA proteins reinforces auxin co-receptor assemblies.

Niemeyer Michael M Moreno Castillo Elena E Ihling Christian H CH Iacobucci Claudio C Wilde Verona V Hellmuth Antje A Hoehenwarter Wolfgang W Samodelov Sophia L SL Zurbriggen Matias D MD Kastritis Panagiotis L PL Sinz Andrea A Calderón Villalobos Luz Irina A LIA

Nature communications 20200508 1

Cullin RING-type E3 ubiquitin ligases SCF<sup>TIR1/AFB1-5</sup> and their AUX/IAA targets perceive the phytohormone auxin. The F-box protein TIR1 binds a surface-exposed degron in AUX/IAAs promoting their ubiquitylation and rapid auxin-regulated proteasomal degradation. Here, by adopting biochemical, structural proteomics and in vivo approaches we unveil how flexibility in AUX/IAAs and regions in TIR1 affect their conformational ensemble allowing surface accessibility of degrons. We resolve TIR1 ...[more]

PMID: 32385295

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