biostudies-literatureKong LNSFCancer Research UKNational Institutes of HealthWellcome TrustNIGMS NIH HHSBiotechnology and Biological Sciences Research CouncilNational Science Foundation4591-4604.e8https://www.ebi.ac.uk/biostudies/studies/S-EPMC8684601biostudies-literatureUnknown81(22)Protein ADP-ribosylation is a reversible post-translational modification that transfers ADP-ribose from NAD⁺ onto acceptor proteins. Poly(ADP-ribosyl)ation (PARylation), catalyzed by poly(ADP-ribose) polymerases (PARPs) and poly(ADP-ribose) glycohydrolases (PARGs), which remove the modification, regulates diverse cellular processes. However, the chemistry and physiological functions of mono(ADP-ribosyl)ation (MARylation) remain elusive. Here, we report that Arabidopsis zinc finger proteins SZF1 and SZF2, key regulators of immune gene expression, are MARylated by the noncanonical ADP-ribosyltransferase SRO2. Immune elicitation promotes MARylation of SZF1/SZF2 via dissociation from PARG1, which has an unconventional activity in hydrolyzing both poly(ADP-ribose) and mono(ADP-riboseMolecular cellNoncanonical mono(ADP-ribosyl)ation of zinc finger SZF proteins counteracts ubiquitination for protein homeostasis in plant immunity.PMC8684601MCB-1906060R01GM09289322284R01 GM092893R01 GM097247101794R01GM097247IOS-1951094210634/Z/18/Z210634C35050/A22284BB/R007195/1Xu LKong LAhel IRack JGMShan LJang JCKim JHFeng BYan YZhang CWang YHe PfalseNoncanonical mono(ADP-ribosyl)ation of zinc finger SZF proteins counteracts ubiquitination for protein homeostasis in plant immunity.Protein ADP-ribosylation is a reversible post-translational modification that transfers ADP-ribose from NAD⁺ onto acceptor proteins. Poly(ADP-ribosyl)ation (PARylation), catalyzed by poly(ADP-ribose) polymerases (PARPs) and poly(ADP-ribose) glycohydrolases (PARGs), which remove the modification, regulates diverse cellular processes. However, the chemistry and physiological functions of mono(ADP-ribosyl)ation (MARylation) remain elusive. Here, we report that Arabidopsis zinc finger proteins SZF1 and SZF2, key regulators of immune gene expression, are MARylated by the noncanonical ADP-ribosyltransferase SRO2. Immune elicitation promotes MARylation of SZF1/SZF2 via dissociation from PARG1, which has an unconventional activity in hydrolyzing both poly(ADP-ribose) and mono(ADP-ribose2021-01-01T00:00:00Z2021 Nov2026-06-01T02:12:25.585Z2025-02-19T01:28:35.007ZS-EPMC86846013459213410.1016/j.molcel.2021.09.006