A 125 kDa RNase E/G-like protein is present in plastids and is essential for chloroplast development and autotrophic growth in Arabidopsis*

Mudd, Elisabeth A.; Sullivan, Stuart; Gisby, Martin F.; Mironov, Aleksandr; Kwon, Chang Seob; Chung, Woosuk; Day, Anil

doi:10.1093/jxb/ern126

Cited by 41 publications

(56 citation statements)

References 75 publications

(107 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Protein concentration was estimated using a Bio-Rad protein assay kit (Bio-Rad Laboratories). Immunoblotting was carried out as described by Mudd et al (2008). Polyclonal antibodies against PTOX were kindly provided by Dr. M. Kuntz (Université Joseph Fourier, Grenoble, France).…”

Section: Measurements Of Ptox Activity and Proteinmentioning

confidence: 99%

Contrasting Responses of Photosynthesis to Salt Stress in the Glycophyte Arabidopsis and the Halophyte Thellungiella: Role of the Plastid Terminal Oxidase as an Alternative Electron Sink

2008

View full text Add to dashboard Cite

The effects of short-term salt stress on gas exchange and the regulation of photosynthetic electron transport were examined in Arabidopsis (Arabidopsis thaliana) and its salt-tolerant close relative Thellungiella (Thellungiella halophila). Plants cultivated on soil were challenged for 2 weeks with NaCl. Arabidopsis showed a much higher sensitivity to salt than Thellungiella; while Arabidopsis plants were unable to survive exposure to greater than 150 mM salt, Thellugiella could tolerate concentrations as high as 500 mM with only minimal effects on gas exchange. Exposure of Arabidopsis to sublethal salt concentrations resulted in stomatal closure and inhibition of CO 2 fixation. This lead to an inhibition of electron transport though photosystem II (PSII), an increase in cyclic electron flow involving only PSI, and increased nonphotochemical quenching of chlorophyll fluorescence. In contrast, in Thellungiella, although gas exchange was marginally inhibited by high salt and PSI was unaffected, there was a large increase in electron flow involving PSII. This additional electron transport activity is oxygen dependent and sensitive to the alternative oxidase inhibitor n-propyl gallate. PSII electron transport in Thellungiella showed a reduced sensitivity to 2#-iodo-6-isopropyl-3-methyl-2#,4,4#-trinitrodiphenylether, an inhibitor of the cytochrome b 6 f complex. At the same time, we observed a substantial up-regulation of a protein reacting with antibodies raised against the plastid terminal oxidase. No such up-regulation was seen in Arabidopsis. We conclude that in salt-stressed Thellungiella, plastid terminal oxidase acts as an alternative electron sink, accounting for up to 30% of total PSII electron flow.

show abstract

Section: Measurements Of Ptox Activity and Proteinmentioning

confidence: 99%

Contrasting Responses of Photosynthesis to Salt Stress in the Glycophyte Arabidopsis and the Halophyte Thellungiella: Role of the Plastid Terminal Oxidase as an Alternative Electron Sink

2008

View full text Add to dashboard Cite

show abstract

“…Homologs of the E. coli RNase E and the B. subtilis RNase J may act as major plastid endonucleases [279]. The Arabidopsis RNase E has a function comparable to its E. coli counterpart: it prefers 5′ monophosphorylated (processed) substrates; it is inhibited by structured RNA; and it preferentially cleaves AU-rich sequences [191,249]. Recent analyses found that RNase E null mutants in Arabidopsis show multiple defects in the processing of polycistronic precursor transcripts [314].…”

Section: Chloroplast Rnasesmentioning

confidence: 99%

Chloroplast Gene Expression—RNA Synthesis and Processing

Börner¹,

Zhelyazkova²,

Legen³

et al. 2014

Plastid Biology

View full text Add to dashboard Cite

Both transcription and transcript processing are more complex in chloroplasts than in bacteria. Plastid genes are transcribed by a plastid-encoded RNA polymerase (PEP) and one (monocots) or two (dicots) nuclear-encoded RNA polymerase(s) (NEP). PEP is a bacterial-type multisubunit enzyme composed of core subunits (coded for by the plastid rpoA, B, C1 and C2 genes) and additional protein factors encoded in the nuclear genome. The nuclear genome of Arabidopsis contains six genes for sigma factors required by PEP for promoter recognition. NEP activity is represented by phage-type RNA polymerases. Factors supporting NEP activity have not been identified yet. NEP and PEP use different promoters. Both types of RNA polymerase are active in proplastids and all stages of chloroplast development. PEP is the dominating transcriptase in chloroplasts.Chloroplast RNA processing consists of hundreds of mostly independent events. In recent years, much progress has been made in identifying factors behind RNA splicing and RNA editing. Namely, pentatricopeptide repeat (PPR) proteins have come into focus as RNA binding proteins conferring specificity to individual processing events. Also, studies on chloroplast RNases have helped considerably to understand chloroplast RNA turnover. Such mechanistic insights are set in contrast to how little we know about the regulatory role of RNA processing in chloroplasts.Keywords Chloroplast transcription · Chloroplast RNA polymerase · Chloroplast promoter · Chloroplast RNA processing · Chloroplast RNA-binding proteins · PPR proteins · Chloroplast splicing · Chloroplast editing · Chloroplast RNA degradation · Chloroplast nucleases Abbreviations CRS2 Chloroplast RNA splicing 2 protein IR Inverted repeat NEP Nuclear-encoded plastid RNA polymerase

show abstract

“…Within higher plants, two chloroplast endonucleases have been identified, RNase E (Mudd et al 2008) and RNase J (Olinares et al 2010). RNase J also harbors 59-to-39 exonuclease nuclease activity, based on studies of the Bacillus subtilis orthologs (for review, see Condon 2010).…”

Section: Rnase E and Rnase J May Mediate Endonuclease Cleavage Withinmentioning

confidence: 99%

Overaccumulation of the chloroplast antisense RNA AS5 is correlated with decreased abundance of 5S rRNA in vivo and inefficient 5S rRNA maturation in vitro

Sharwood¹,

Hotto²,

Bollenbach³

et al. 2010

RNA

View full text Add to dashboard Cite

Post-transcriptional regulation in the chloroplast is exerted by nucleus-encoded ribonucleases and RNA-binding proteins. One of these ribonucleases is RNR1, a 39-to-59 exoribonuclease of the RNase II family. We have previously shown that Arabidopsis rnr1-null mutants exhibit specific abnormalities in the expression of the rRNA operon, including the accumulation of precursor 23S, 16S, and 4.5S species and a concomitant decrease in the mature species. 5S rRNA transcripts, however, accumulate to a very low level in both precursor and mature forms, suggesting that they are unstable in the rnr1 background. Here we demonstrate that rnr1 plants overaccumulate an antisense RNA, AS5, that is complementary to the 5S rRNA, its intergenic spacer, and the downstream trnR gene, which encodes tRNA Arg , raising the possibility that AS5 destabilizes 5S rRNA or its precursor and/or blocks rRNA maturation. To investigate this, we used an in vitro system that supports 5S rRNA and trnR processing. We show that AS5 inhibits 5S rRNA maturation from a 5S-trnR precursor, and shorter versions of AS5 demonstrate that inhibition requires intergenic sequences. To test whether the sense and antisense RNAs form double-stranded regions in vitro, treatment with the single-strand-specific mung bean nuclease was used. These results suggest that 5S-AS5 duplexes interfere with a sense-strand secondary structure near the endonucleolytic cleavage site downstream from the 5S rRNA coding region. We hypothesize that these duplexes are degraded by a dsRNA-specific ribonuclease in vivo, contributing to the 5S rRNA deficiency observed in rnr1.

show abstract

A 125 kDa RNase E/G-like protein is present in plastids and is essential for chloroplast development and autotrophic growth in Arabidopsis*

Cited by 41 publications

References 75 publications

Contrasting Responses of Photosynthesis to Salt Stress in the Glycophyte Arabidopsis and the Halophyte Thellungiella: Role of the Plastid Terminal Oxidase as an Alternative Electron Sink

Contrasting Responses of Photosynthesis to Salt Stress in the Glycophyte Arabidopsis and the Halophyte Thellungiella: Role of the Plastid Terminal Oxidase as an Alternative Electron Sink

Chloroplast Gene Expression—RNA Synthesis and Processing

Overaccumulation of the chloroplast antisense RNA AS5 is correlated with decreased abundance of 5S rRNA in vivo and inefficient 5S rRNA maturation in vitro

Contact Info

Product

Resources

About