RCD1–DREB2A interaction in leaf senescence and stress responses in Arabidopsis thaliana

Abstract

Transcriptional regulation of gene expression is one major determinant of developmental control and stress adaptation in virtually all living organisms. In recent years numerous transcription factors controlling various aspects of plant life have been identified. The activity of transcription factors needs to be regulated to prevent unspecific, prolonged or inappropriate responses. The transcription factor DREB2A (DEHYDRATION-RESPONSIVE ELEMENT BINDING 2A) has been identified as one of the main regulators of drought and heat responses, and it is regulated through protein stability. In the present paper we describe evidence that the interaction with RCD1 (RADICAL-INDUCED CELL DEATH 1) contributes to the control of DREB2A under a range of conditions. The interaction is mediated by a novel protein motif in DREB2A and a splice variant of DREB2A which lacks the interaction domain accumulates during heat stress and senescence. In addition RCD1 is rapidly degraded during heat stress, thus our results suggest that removal of RCD1 protein or the loss of the interaction domain in DREB2A appears to be required for proper DREB2A function under stress conditions.

The Membrane-Bound NAC Transcription Factor ANAC013 Functions in Mitochondrial Retrograde Regulation of the Oxidative Stress Response in Arabidopsis

“…As RCD1 is localized in the nucleus under nonstressed conditions and rcd1 mutants exhibit an elevated expression of ANAC013 target genes, RCD1 might negatively affect the ANAC013 function in the nucleus in the absence of stress (Jaspers et al, 2009). Similarly, RCD1 negatively regulates the stability of the DEHYDRATION-RESPONSE ELEMENT BINDING PROTEIN2A (DREB2A) transcription factor but is rapidly degraded upon stress, promoting the proper DREB2A function under these conditions (Vainonen et al, 2012). Furthermore, it might be necessary for correct meristem function, presumably by influencing the redox/ROS balance (Teotia and Lamb, 2011).…”

Towards Understanding Extracellular ROS Sensory and Signaling Systems in Plants

“…This domain is completely located in an exon that is a subject to developmental alternative splicing; for example, the domain is absent in DREB2A in leaves approaching senescence. Conserved amino acid residues within the RCD1-interaction motif in DREB2A 2B and 2C are required for the interaction with RCD1 [34]. Thus the interaction between RCD1 and at least some transcription factors is very specific and regulated by both partners.…”

“…The most prominent RCD1-interacting protein through the RST domain is DREB2A (and also DREB2B and DREB2C, but no other member of the DREB2-protein family), a transcription factor of central importance in plant acclimation to several abiotic stresses in the ABAindependent signaling pathway [61]. The DREB2A B and C proteins have a specific domain which we showed to interact with RCD1 [34]. This domain is completely located in an exon that is a subject to developmental alternative splicing; for example, the domain is absent in DREB2A in leaves approaching senescence.…”

“…For example, double mutant analysis suggests a role for RCD1 in retrograde signaling from multiple organelles. We have shown that the rcd1 mutant is sensitive to [34], and a C-terminal protein-protein interaction domain RST which mediates specific interaction with several transcription factors [35]. (b) Poly(ADP)ribosylation is mediated by the activity of PARP (poly(ADP)ribose polymerase), which transfers ADP-ribose from NAD + to a target protein forming poly(ADP) ribose (PAR).…”

“…The RCD protein has N-terminal nuclear localization sequences, a WWE domain found in proteins involved in ubiquitination and ADP ribosylation, a "PARP" domain poly(ADP-ribosyl)ation domain, which does not have PARP activity [34]), and a C-terminal protein-protein interaction domain (Figure 2(a)). The WWE domain is a common interaction module in proteins involved in posttranslational regulation of protein stability by ubiquitination and ADP ribosylation and has been shown to bind the iso-ADP-ribose moiety in poly(ADP-ribose) [60].…”