The RING finger E3 ligase STRF1 is involved in membrane trafficking and modulates salt‐stress response in Arabidopsis thaliana

Abstract

These authors contribute equally to this work. SUMMARYSalt stress is a detrimental factor for plant growth and development. The response to salt stress has been shown to involve components in the intracellular trafficking system, as well as components of the ubiquitin-proteasome system (UPS). In this article, we have identified in Arabidopsis thaliana a little reported ubiquitin ligase involved in salt-stress response, which we named STRF1 (Salt Tolerance RING Finger 1). STRF1 is a member of RING-H2 finger proteins and we demonstrate that it has ubiquitin ligase activity in vitro. We also show that STRF1 localizes mainly at the plasma membrane and at the intracellular endosomes. strf1-1 loss-of-function mutant seedlings exhibit accelerated endocytosis in roots, and have altered expression of several genes involved in the membrane trafficking system. Moreover, protein trafficking inhibitor, brefeldin A (BFA), treatment has increased BFA bodies in strf1-1 mutant. This mutant also showed increased tolerance to salt, ionic and osmotic stresses, reduced accumulation of reactive oxygen species during salt stress, and increased expression of AtRbohD, which encodes a nicotinamide adenine dinucleotide phosphate (NADPH) oxidase involved in H 2 O 2 production. We conclude that STRF1 is a membrane trafficking-related ubiquitin ligase, which helps the plant to respond to salt stress by monitoring intracellular membrane trafficking and reactive oxygen species (ROS) production.

The Arabidopsis Gene zinc finger protein 3(ZFP3) Is Involved in Salt Stress and Osmotic Stress Response

“…High salt stress can cause osmotic and ionic stress [1,13]. Salt stress involved in ionic homeostasis pathway was discovered by cloning the salt overly sensitive ( SOS ) genes.…”

Genome-wide identification, evolution and expression analysis of RING finger protein genes in Brassica rapa

“…For example, In A. thaliana, BRH1 is involved in brassinosteroid-responsive19, RIE1 in seed development20, ATL2/ATL9 in defense response2122, XERICO in drought tolerance23, KEG in growth and development24, PEX2/PEX10/PEX12 in peroxisome formation2526, NLA in adaptability to nitrogen limitation27, SHA1 in shoot apical meristem maintenance28, SDIR1 in stress-responsive abscisic acid signaling29, DRIP1 / DRIP2 is in drought response30 , RHA2a/RHA2b in ABA-mediated stress signaling3132, CNI1 in the carbon/nitrogen response for growth phase transition33, SIS3 in sugar response34, XBAT32 in lateral root production by regulating the ethylene biosynthesis35, AtAIRP1 in ABA-dependent response to drought stress36, DAL1/DAL2 in regulation of programmed cell death37, DAF in anther dehiscence38, AtAIRP3 in high-salt and drought stress responses39, RSL1 in seed longevity40, AtRING1A in flowering41, COP1 in photomorphogenesis42, NERF in drought resistance43, STRF1 in salt-stress response44; in B. rapa, BrRZFP1 is involved in cold, salt and dehydration stress45; in B. napus, Bnclg1A-1D is involved in cleistogamy trait formation46.…”

An ATL78-Like RING-H2 Finger Protein Confers Abiotic Stress Tolerance through Interacting with RAV2 and CSN5B in Tomato

“…The RING finger ubiquitin E3 ligase SDIR1 targets SDIR1-INTERACTING PROTEIN1 to modulate the salt stress response and ABA signaling in Arabidopsis (Zhang et al, 2015). Another RING finger E3 ligase, STRF1, is a membrane trafficking-related ubiquitin ligase, which helps the plants to respond to salt stress by monitoring intracellular membrane trafficking and ROS production (Tian et al, 2015). …”

“…The RING finger domain appears to be a convenient scaffold that can be altered to provide functional specificity and the RING finger motif is defined as Cys-X2-Cys-X(9–39)-Cys-X(1–3)-His-X(2–3)-Cys/His-X2-Cys-X(4–48)-Cys-X2-Cys, where X is any amino acid (Borden and Freemont, 1996). Functional studies of the RING finger proteins revealed their wide range of roles in various biological processes including viral replication, signal transduction, and development (Tian et al, 2015). In contrast to two canonical RING types (C3H2C3 or C3HC4), additional types of modified RING domains including RING-V, RING-D, RING-S/T, RING-G, and RING-C2, were identified in Arabidopsis (Stone et al, 2005).…”