The E3 ligase OsPUB15 interacts with the receptor-like kinase PID2 and regulates plant cell death and innate immunity

Abstract

BackgroundRice blast disease is one of the most destructive diseases of rice worldwide. We previously cloned the rice blast resistance gene Pid2, which encodes a transmembrane receptor-like kinase containing an extracellular B-lectin domain and an intracellular serine/threonine kinase domain. However, little is known about Pid2-mediated signaling.ResultsHere we report the functional characterization of the U-box/ARM repeat protein OsPUB15 as one of the PID2-binding proteins. We found that OsPUB15 physically interacted with the kinase domain of PID2 (PID2K) in vitro and in vivo and the ARM repeat domain of OsPUB15 was essential for the interaction. In vitro biochemical assays indicated that PID2K possessed kinase activity and was able to phosphorylate OsPUB15. We also found that the phosphorylated form of OsPUB15 possessed E3 ligase activity. Expression pattern analyses revealed that OsPUB15 was constitutively expressed and its encoded protein OsPUB15 was localized in cytosol. Transgenic rice plants over-expressing OsPUB15 at early stage displayed cell death lesions spontaneously in association with a constitutive activation of plant basal defense responses, including excessive accumulation of hydrogen peroxide, up-regulated expression of pathogenesis-related genes and enhanced resistance to blast strains. We also observed that, along with plant growth, the cell death lesions kept spreading over the whole seedlings quickly resulting in a seedling lethal phenotype.ConclusionsThese results reveal that the E3 ligase OsPUB15 interacts directly with the receptor-like kinase PID2 and regulates plant cell death and blast disease resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0442-4) contains supplementary material, which is available to authorized users.

The Monocot-Specific Receptor-like Kinase SDS2 Controls Cell Death and Immunity in Rice

“…OsPUB15 and Pid2 module both rice PTI and ETI. The Medicago PUB1 regulates root nodulation and symbiosis of Rhizobial and Arbuscular Mycorrhizal together with LYK3 and DMI2 (Trujillo, 2018; Wang et al, 2015). In addition, PUB proteins are reported to form conserved modules with S-domain-1-type RLKs in Arabidopsis (Samuel et al, 2008).…”

MAC3A and MAC3B, Two Core Subunits of the MOS4-Associated Complex, Positively Influence miRNA Biogenesis

“…However, MBP-MAC3A 321 displayed only weak activity ( Figure 7B). We suspected that like some other E3 ligases, MAC3A 322 activity might depend on post-translational modification (Wang et al, 2015). Thus, we treated 323 MBP-MAC3A and MBP protein with total protein extracts from inflorescences of mac3a mac3b.…”

“…The in vitro ubiquitination assay was performed as described (Zhou et al, 2017) protein modification on MAC3A activity, the recombinant proteins were treated as previously 485 described with modifications (Wang et al, 2015). Briefly, 4 µg MBP, MBP-MAC3A, MBP-486…”

Homologous U-box E3 Ubiquitin Ligases OsPUB2 and OsPUB3 Are Involved in the Positive Regulation of Low Temperature Stress Response in Rice (Oryza sativa L.)

“…Rice U-box E3 Ub ligases are implicated in biotic stress responses such as innate immunity and PAMP-triggered cell death (Zeng et al, 2004; Ishikawa et al, 2014; Liu et al, 2015; Wang et al, 2015). Recent genome-wide expression analysis showed that OsPUBs , which contain the ARM repeat motif, are induced by a broad spectrum of abiotic stress, suggesting their roles in the response to environmental stimuli in rice plants (Sharma et al, 2014).…”

“…OsPUB15 is involved in reducing cellular oxidative stress during seedling establishment (Park et al, 2011). OsPUB15 interacts with the receptor-like kinase PID2 and regulates cell death and immunity (Wang et al, 2015). OsPUB44 was found to be positively involved in PAMP-triggered immunity (Ishikawa et al, 2014).…”