PXD073328-1

PXD073328 is an original dataset announced via ProteomeXchange.

Title	CATALASE INTERACTING RCC1-LIKE 1 contributes to hydrogen peroxide homeostasis in Arabidopsis
Description	Reactive oxygen species (ROS) are central regulators of plant growth and stress responses, and their cellular levels are tightly controlled by antioxidant systems, including the evolutionarily conserved catalases that decompose hydrogen peroxide (H2O2) predominantly within peroxisomes and glyoxysomes. Despite their importance, key aspects of catalase biogenesis, regulation, subcellular targeting, and potential extra-peroxisomal functions remain poorly understood. Using affinity purification of the UV-B photoreceptor UVR8 coupled with mass spectrometry, we identified a REGULATOR OF CHROMATIN CONDENSATION 1–like protein in Arabidopsis, which we named CATALASE-INTERACTING RCC1-LIKE 1 (CAIR1). CAIR1 interacts with all three catalase isoforms (CAT1–CAT3) as well as their chaperone NO CATALASE ACTIVITY 1 (NCA1). Loss-of-function cair1 mutants partially phenocopy cat2 and nca1, exhibiting reduced catalase activity, enhanced sensitivity to oxidative stress and alkaline growth conditions, and impaired primary root elongation. Mechanistically, cytosolic interaction between CAIR1 and CAT2 enhances total cellular catalase activity by facilitating peroxisomal import and proper subcellular localization of CAT2. In the absence of CAIR1, CAT2 forms aggregates, likely accounting for the observed loss of catalase activity. Notably, CAIR1 undergoes reversible, redox-dependent oligomerization that strengthens its interaction with catalases. Mutation of CAIR1 at Cys-356 and Cys-545 compromises this interaction under elevated ROS conditions and fails to rescue the oxidative stress sensitivity of cair1 mutants. Moreover, UV-B exposure suppresses catalase activity by weakening the interaction between CAIR1 and catalases, linking environmental light signaling to cellular redox regulation. Together, our findings reveal CAIR1 as a dynamic redox-responsive regulator of catalase activity that maintains cellular redox homeostasis by coordinating catalase localization and function through reversible oligomerization.
HostingRepository	PRIDE
AnnounceDate	2026-07-15
AnnouncementXML	Submission_2026-07-15_07:55:09.485.xml
DigitalObjectIdentifier
ReviewLevel	Peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Sara Christina Stolze
SpeciesList	scientific name: Arabidopsis thaliana (Mouse-ear cress); NCBI TaxID: NEWT:3702;
ModificationList	No PTMs are included in the dataset
Instrument	Orbitrap Exploris 480; Q Exactive; Q Exactive Plus

Revision	Datetime	Status	ChangeLog Entry
0	2026-01-21 01:45:16	ID requested
⏵ 1	2026-07-15 07:55:10	announced

Dataset with its publication pending

submitter keyword: H2O2 homeostasis, plant growth, Arabidopsis thaliana, stress-response, RCC1-like protein

Hirofumi Nakagami
contact affiliation	Basic Immune System of Plants / Protein Mass Spectrometry Max Planck Institute for Plant Breeding Research Carl-von-Linne-Weg 10, 50829 Cologne, Germany
contact email	nakagami@mpipz.mpg.de
lab head
Sara Christina Stolze
contact affiliation	Plant Proteomics and Mass Spectrometry Group Max Planck Institute for Plant Breeding Research Carl-von-Linné Weg 10 50829 Cologne
contact email	stolze@mpipz.mpg.de
dataset submitter

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PRIDE project URI

• PRIDE
  1. PXD073328
     1. Label: PRIDE project
     2. Name: CATALASE INTERACTING RCC1-LIKE 1 contributes to hydrogen peroxide homeostasis in Arabidopsis