HCN Regulates Cellular Processes through Posttranslational Modification of Proteins by S-cyanylation. Issue 1 (30th October 2018)

• Record Type: Journal Article
• Authors: García, Irene; Arenas-Alfonseca, Lucía; Moreno, Inmaculada; Gotor, Cecilia; Romero, Luis C.
• Is Part Of: Plant physiology. Volume 179:Issue 1(2019)
• Page Start: 107
• Page End: 123
• Publication Date: 2018-10-30
• Subjects: Plant physiology -- Periodicals; Botany -- Periodicals; Periodicals; Electronic journals; 571.2
• DOI: 10.1104/pp.18.01083
• Languages: English
• ISSNs: 0032-0889

Abstract

Abstract : Hydrogen cyanide can act as a signaling molecule through posttranslational modification of protein cysteine residues, leading to S-cyanylation. Abstract: 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 Cys 74, CYP20-3 Cys 259, and ENO2 Cys 346 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.