Publication Information
García et al., 2019
Abstract
Plant Physiol. 2019 Jan;179(1):107-123. doi: 10.1104/pp.18.01083. Epub 2018 Oct
30.
HCN Regulates Cellular Processes through Posttranslational Modification of
Proteins by S-cyanylation.
García I(1), Arenas-Alfonseca L(1), Moreno I(1), Gotor C(1), Romero LC(2).
Author information:
(1)Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de
Investigaciones Científicas and Universidad de Sevilla, Avenida Américo
Vespucio, 49, 41092 Sevilla, Spain.
(2)Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de
Investigaciones Científicas and Universidad de Sevilla, Avenida Américo
Vespucio, 49, 41092 Sevilla, Spain lromero@ibvf.csic.es.
Hydrogen cyanide (HCN) is coproduced with ethylene in plant cells and is
primarily enzymatically detoxified by the mitochondrial β-CYANOALANINE SYNTHASE
(CAS-C1). Permanent or transient depletion of CAS-C1 activity in Arabidopsis
(Arabidopsis thaliana) results in physiological alterations in the plant that
suggest that HCN acts as a gasotransmitter molecule. Label-free quantitative
proteomic analysis of mitochondrially enriched samples isolated from the wild
type and cas-c1 mutant revealed significant changes in protein content,
identifying 451 proteins that are absent or less abundant in cas-c1 and 353
proteins that are only present or more abundant in cas-c1 Gene ontology
classification of these proteins identified proteomic changes that explain the
root hairless phenotype and the altered immune response observed in the cas-c1
mutant. The mechanism of action of cyanide as a signaling molecule was addressed
using two proteomic approaches aimed at identifying the S-cyanylation of Cys as
a posttranslational modification of proteins. Both the 2-imino-thiazolidine
chemical method and the direct untargeted analysis of proteins using liquid
chromatography-tandem mass spectrometry identified a set of 163 proteins
susceptible to S-cyanylation that included SEDOHEPTULOSE 1,7-BISPHOSPHATASE
(SBPase), the PEPTIDYL-PROLYL CIS-TRANS ISOMERASE 20-3 (CYP20-3), and ENOLASE2
(ENO2). In vitro analysis of these enzymes showed that S-cyanylation of SBPase
Cys74, CYP20-3 Cys259, and ENO2 Cys346 residues affected their enzymatic
activity. Gene Ontology classification and protein-protein interaction cluster
analysis showed that S-cyanylation is involved in the regulation of primary
metabolic pathways, such as glycolysis, and the Calvin and S-adenosyl-Met
cycles.
© 2019 American Society of Plant Biologists. All Rights Reserved.
DOI: 10.1104/pp.18.01083
PMCID: PMC6324243
PMID: 30377236 [Indexed for MEDLINE]
