RETRACTED ARTICLE:The Arabidopsis NOT4A E3 ligase promotes PGR3 expression and regulates chloroplast translation

Abstract

Chloroplast function requires the coordinated action of nuclear- and chloroplast-derived proteins, including several hundred nuclear-encoded pentatricopeptide repeat (PPR) proteins that regulate plastid mRNA metabolism. Despite their large number and importance, regulatory mechanisms controlling PPR expression are poorly understood. Here we show that the Arabidopsis NOT4A ubiquitin-ligase positively regulates the expression of PROTON GRADIENT REGULATION 3 (PGR3), a PPR protein required for translating several thylakoid-localised photosynthetic components and ribosome subunits within chloroplasts. Loss of NOT4A function leads to a strong depletion of cytochrome b6f and NAD(P)H dehydrogenase (NDH) complexes, as well as plastid 30 S ribosomes, which reduces mRNA translation and photosynthetic capacity, causing pale-yellow and slow-growth phenotypes. Quantitative transcriptome and proteome analysis of the not4a mutant reveal it lacks PGR3 expression, and that its molecular defects resemble those of a pgr3 mutant. Furthermore, we show that normal plastid function is restored to not4a through transgenic PGR3 expression. Our work identifies NOT4A as crucial for ensuring robust photosynthetic function during development and stress-response, through promoting PGR3 production and chloroplast translation.

A DELAY OF GERMINATION 1 (DOG1)‐like protein regulates spore germination in the moss Physcomitrium patens

“…Western blotting and yeast two hybrid including transformation of Matchmaker (AH109) yeast was performed as described in Bailey et al. (2021) and Phokas et al. (2023).…”

“…Western blotting and yeast two hybrid including transformation of Matchmaker (AH109) yeast was performed as described in Bailey et al (2021) and Phokas et al (2023). Briefly, for yeast transformation, single colonies cultured on YPAD agar medium (20 g L À1 bacto-peptone, 10 g L À1 bacto-yeast extract, 20 g L À1 dextrose, 40 mg L À1 adenine sulfate, 20 g L À1 bacto-agar) were resuspended in 100 μl transformation buffer (2:1 50% PEG 3350MW, 1 M lithium acetate, 0.6% β-mercaptoethanol).…”

Exploring the RNA Editing Events and Their Potential Regulatory Roles in Tea Plant (Camellia sinensis L.)

“…RNA editing seemed to be a challenge to the central dogma of molecular biology at the transcriptional level, and has received increasing attention [ 2 , 3 ]. In recent years, a large number of RNA editing factors were reported to be involved in the C-to-U deamination reaction [ 39 , 40 , 41 ], and many studies attempted to use expressed sequence tags (EST) sequences [ 42 ] or high-throughput sequencing technology to identify additional RNA editing sites in plants [ 43 , 44 ]. Moreover, in order to distinguish the changed sites due to heteroplasmy or the RNA editing events, total RNA-seq as well as DNA-seq was used for analysis [ 45 ], but the heteroplasmy could not be excluded in this work.…”