Proteomic data of A. thaliana WT vs. rpn8a, sp1 and ppi2 vs.sp1xppi2, rpn8axppi2

ABSTRACT: A mutation in the proteasomal lid subunit Rpn8a alters proteasome composition and exerts a beneficial effect on photosynthesis. The effect is particularly visible in a double mutant between rpn8a and the plastid protein import receptor Toc159 (ppi2xrpn8a) but also in an rpn8a single mutant that shows higher PSII efficiency and lower non-photochemical quenching. The double mutant shows elevated accumulation of pigments, higher levels of thylakoid membrane proteins and higher PSII quantum yield compared to the ppi2 single mutant. While proplastid-like pro-thylakoid structures are characteristic for ppi2, stacked thylakoids are frequently observed in the double mutant. The rpn8a mutation is accompanied by higher 20S and lower 26S proteasome abundance and increased expression levels of proteolytic stress markers. Unlike known retrograde signaling chains, there is no effect on the transcription of selected photosynthesis associated nuclear encoded gens (PhanGs). Since plastid precursor protein abundance is elevated in the double mutant it is conceivable that the changes in proteasome composition affect precursor stability. We propose a model in which mild proteasome impairment shifts the equilibrium between precursor import and degradation towards import, which is especially effective in plastid protein import mutants but also detectable in the wildtype background, albeit to a much weaker extent.

INSTRUMENT(S): Synapt MS

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Plant Cell, Root, Leaf, Rosette, Shoot

SUBMITTER: Sacha Baginsky  

LAB HEAD: Sacha Baginsky

PROVIDER: PXD014531 | Pride | 2020-05-27

REPOSITORIES: Pride