title: Cysteine and cysteine-related signaling pathways in Arabidopsis thaliana.
abstract: Cysteine occupies a central position in plant metabolism because it is a reduced sulfur donor molecule involved in the synthesis of essential biomolecules and defense compounds. Moreover, cysteine per se and its derivative molecules play roles in the redox signaling of processes occurring in various cellular compartments. Cysteine is synthesized during the sulfate assimilation pathway via the incorporation of sulfide to O-acetylserine, catalyzed by O-acetylserine(thiol)lyase (OASTL). Plant cells contain OASTLs in the mitochondria, chloroplasts, and cytosol, resulting in a complex array of isoforms and subcellular cysteine pools. In recent years, significant progress has been made in Arabidopsis, in determining the specific roles of the OASTLs and the metabolites produced by them. Thus, the discovery of novel enzymatic activities of the less-abundant, like DES1 with L-cysteine desulfhydrase activity and SCS with S-sulfocysteine synthase activity, has provided new perspectives on their roles, besides their metabolic functions. Thereby, the research has been demonstrated that cytosolic sulfide and chloroplastic S-sulfocysteine act as signaling molecules regulating autophagy and protecting the photosystems, respectively. In the cytosol, cysteine plays an essential role in plant immunity; in the mitochondria, this molecule plays a central role in the detoxification of cyanide, which is essential for root hair development and plant responses to pathogens.
authors.affiliation: Instituto de Bioquímica Vegetal y Fotosíntesis, Consejo Superior de Investigaciones Científicas and Universidad de Sevilla, Avenida Américo Vespucio, 49, 41092 Sevilla, Spain.
authors.forename: Luis C
authors.initials: LC
authors.lastname: Romero
authors.forename: M Ángeles
authors.initials: MÁ
authors.lastname: Aroca
authors.forename: Ana M
authors.initials: AM
authors.lastname: Laureano-Marín
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Moreno
authors.forename: Irene
authors.initials: I
authors.lastname: García
authors.forename: Cecilia
authors.initials: C
authors.lastname: Gotor
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D008928:Mitochondria / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D003545:Cysteine
keywords: O-acetylserine(thiol)lyase; S-sulfocysteine synthase; cyanide; cysteine desulfhydrase; plant development; plant immunity; redox signaling; stress; sulfide.; β-cyanoalanine synthase