Proteome Analysis of the ROF-FKBP Mutants Reveals
Functional Relations among Heat Stress Responses, Plant Development,
and Protein Quality Control during Heat Acclimation in Arabidopsis thaliana
posted on 2023-12-26, 23:29authored byParaskevi Lefa, Martina Samiotaki, Theodora Farmaki
In the present study,
a differential screening following heat stress
acclimation was performed in Arabidopsis thaliana WT and ROF-FKBP mutated plants using mass spectrometry, and the
results were used to understand and analyze the effect of the ROF
PPIases during thermotolerance acquisition in plants. Our data highlight
the central role of these two PPIases in heat stress and point to
their direct or indirect effect on other proteins participating in
cellular functions such as protein folding and quality control, cell
division, photosynthesis, and other metabolic and signaling processes.
Specifically, the heat stress response, protein folding, and protein
ER processing pathways are enhanced following a 37 °C acclimation
period independent of the mutation state. However, at 37 °C,
and in the double-mutated rof1–/2– plants,
a higher accumulation of proteins belonging to the above pathways
is observed compared with all other conditions (WT, single mutants,
control, and heat-acclimated plants). Furthermore, the proteasomal
pathway, involving the common member of both the protasomal and the
lysosomal degradation pathway, CDC48, is over-represented in the extracts
of both the untreated and heat-stressed rof1–/2– mutants compared with the other extracts. In contrast, in
the single rof1– mutation, the heat acclimation pathway is suppressed at 37 °C
when compared to the WT. Protein accumulation related to the heat
stress and the protein quality control pathways points to a differential
but also synergistic role of the two proteins. Protein complexes of
other biochemical and developmental mechanisms, such as the light-harvesting
complex of the photosynthetic pathway and the phosphoinositide binding
proteins involved in membrane-trafficking events during cell plate
formation and cytokinesis (patellin 1, 2, and 4), are negatively regulated
in the rof1–/2– mutant. Our results
suggest that ROF1 and ROF2 FKBPs regulate stress response, and developmental
and metabolic pathways via a complex feedback mechanism involving
partners that ensure protein quality control and plant survival during
heat stress.