EXECUTER2 modulates the EXECUTER1 signalosome through its singlet oxygen-dependent oxidation

Dogra, Vivek; Singh, Rahul Mohan; Li, Mengping; Li, Mingyue; Singh, Somesh; C, Kim

doi:10.1016/j.molp.2021.12.016

Cited by 31 publications

(25 citation statements)

References 64 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Adding to the complexity, recent work suggests these two proteins have different functions. EX2 may act as a decoy to protect EX1 from oxidation and prevent premature signaling (Dogra et al 2022). Thus, a double mutant may have a more complicated phenotype than previously assumed.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Multiple pathways mediate chloroplast singlet oxygen stress signaling

Tano

Kozlowska

Easter

et al. 2022

Preprint

View full text Add to dashboard Cite

Chloroplasts can respond to stress and changes in the environment by producing reactive oxygen species (ROS). Aside from being cytotoxic, ROS also have signaling capabilities. For example, the ROS singlet oxygen (1O2) can initiate nuclear gene expression, chloroplast degradation, and cell death. To unveil the signaling mechanisms involved, researchers have used several 1O2-producing Arabidopsis thaliana mutants as genetic model systems, including plastid ferrochelatase two (fc2), fluorescent in blue light (flu), chlorina 1 (ch1), and accelerated cell death 2 (acd2). Here, we compare these 1O2-producing mutants to elucidate if they utilize one or more signaling pathways to control cell death and nuclear gene expression. Using publicly available transcriptomic data, we demonstrate fc2, flu, and ch1 share a core response to 1O2 accumulation, but maintain unique responses, potentially tailored to respond to their specific stresses. Subsequently, we used a genetic approach to determine if these mutants share 1O2 signaling pathways by testing the ability of genetic suppressors of one 1O2 producing mutant to suppress signaling in a different 1O2 producing mutant. Our genetic analyses revealed at least two different chloroplast 1O2 signaling pathways control cellular degradation: one specific to the flu mutant and one shared by fc2, ch1, and acd2 mutants, but with life-stage-specific (seedling vs. adult) features. Overall, this work reveals chloroplast stress signaling involving 1O2 is complex and may allow cells to finely tune their physiology to environmental inputs.

show abstract

Section: Discussionmentioning

confidence: 99%

“…Like EX1, EX2 undergoes oxidation by 1 O 2 at a conserved tryptophan residue and is subsequently degraded by FtsH2. However, degraded EX2 does not initiate retrograde signaling and cell death like EX1 (Dogra et al 2022). Thus, EX2 may act as a decoy to protect EX1 and attenuate 1 O 2 signals to prevent excessive responses.…”

Section: Introductionmentioning

confidence: 99%

Multiple pathways mediate chloroplast singlet oxygen stress signaling

Tano

Kozlowska

Easter

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…Intact chloroplasts were isolated from the foliar tissues of 3-week-old atrsmD transgenic plants expressing pAtRsmD:AtRsmD-4×Myc grown under CL conditions as described previously (38). Isolated chloroplasts were subfractionated into stroma, envelope membrane, and thylakoid fractions according to the method described previously (50,51). Briefly, purified intact chloroplasts were incubated in hypotonic lysis buffer (25 mM HEPES-KOH [pH 8.0) containing 1× Complete protease inhibitor cocktail [Roche]) for 1 h at 4°C with gentle agitation.…”

Section: Methodsmentioning

confidence: 99%

Section: Chloroplast Purification and Subfractionationmentioning

confidence: 99%

Plastid-specific RsmD methyltransferase and ribosome maturation factor RimM are crucial for 16S rRNA maturation and proteostasis

Liu

Lee

Duan

et al. 2022

Preprint

Self Cite

View full text Add to dashboard Cite

Chloroplast pre-ribosomal RNA (rRNA) undergoes maturation, which is critical for ribosome assembly. While the central and auxiliary factors in rRNA maturation have been elucidated in bacteria, their mode of action remains largely unexplored in chloroplasts. We now reveal chloroplast-specific factors involved in 16S rRNA maturation, RsmD methyltransferase (AtRsmD) and ribosome maturation factor RimM-like protein (AtRimM) in Arabidopsis thaliana. A forward genetic screen aimed to find suppressors of the Arabidopsis yellow variegated 2 (var2) mutant defective in photosystem II (PSII) quality control found a causal nonsense mutation in AtRsmD. The substantially impaired 16S rRNA maturation and translation due to the mutation rescued the leaf variegation phenotype by lowering the levels of PSII core proteins in var2. The subsequent co-immunoprecipitation coupled with mass spectrometry analyses and bimolecular fluorescence complementation assay found that AtRsmD interacts with AtRimM. Consistent with their interaction, loss of AtRimM also considerably impairs 16S rRNA maturation, with less methylation in m2G915 in 16S rRNA catalyzed by AtRsmD. The atrimM mutation also rescued var2 mutant phenotypes, corroborating the functional interplay between AtRsmD and AtRimM towards 16S rRNA maturation and chloroplast proteostasis.

show abstract

“…Hydrogen peroxide (H 2 O 2 ) has been reported to move directly from the chloroplasts to the nucleus and chloroplasts are often associated with the nucleus under stress conditions [ 18 , 20 ]. Singlet Oxygen can directly oxidize the proteins Executer 1 (EX1) and Executer 2 (EX2) and the equilibrium between the two oxidation modulates retrograde signaling [ 21 , 22 ].…”

Section: Why Plants Need To Regulate Chloroplasts Activitymentioning

confidence: 99%

Coordination of Chloroplast Activity with Plant Growth: Clues Point to TOR

D’Alessandro

2022

Plants

View full text Add to dashboard Cite

Photosynthesis is the defining function of most autotrophic organisms. In the plantae kingdom, chloroplasts host this function and ensure growth. However, these organelles are very sensitive to stressful conditions and the photosynthetic process can cause photooxidative damage if not perfectly regulated. In addition, their function is energivorous in terms of both chemical energy and nutrients. To coordinate chloroplast activity with the cell’s need, continuous signaling is required: from chloroplasts to cytoplasm and from nucleus to chloroplasts. In this opinion article, several mechanisms that ensure this communication are reported and the many clues that point to an important role of the Target of Rapamycin (TOR) kinase in the coordination between the eukaryotic and prokaryotic sides of plants are highlighted.

show abstract

EXECUTER2 modulates the EXECUTER1 signalosome through its singlet oxygen-dependent oxidation

Cited by 31 publications

References 64 publications

Multiple pathways mediate chloroplast singlet oxygen stress signaling

Multiple pathways mediate chloroplast singlet oxygen stress signaling

Plastid-specific RsmD methyltransferase and ribosome maturation factor RimM are crucial for 16S rRNA maturation and proteostasis

Coordination of Chloroplast Activity with Plant Growth: Clues Point to TOR

Contact Info

Product

Resources

About