The prion-like proteins have a unique biochemical memory through destructive self-organizing changes of conformation and function. They have a general biological nature, and their behavior was widely studied in mammals, bacteria, and fungi. For less than a dozen plant species, this process, the acquisition of prion properties by proteins are reported in the scientific literature, but they do not have a clear evidence base as well for the appearance of amyloid fibrils. Recently, we and other authors suggested that stress factors might cause a protein with prion-like properties in plant. However, available data is preliminary and hardly convincing. Therefore, it is timely to explore if selected plant proteins, having crucial biochemical functions, such as cupins, auxin-binding proteins, RuBisCo and other photosynthetic proteins, can acquire prion-like properties due to influence of the abiotic chronic stress factors.
The aim of our study is the transition of the α-structure to β-conformation in proteins and the appearance of amyloid aggregates in plant cells challenged by suboptimal conditions under influence abiotic stress factors using state-of-the-art proteomics, microscopy, and molecular biology.
Our previous studies showed that under chronic irradiation in the Chernobyl zone flax accumulates proteins with prion-like properties (Gábrišová et al., 2016). Moreover, we demonstrated with FTIR spectrometry that in X-ray-irradiated Arabidopsis thaliana transition of the α-state of proteins to β-conformation increased by 12% (Litvinov et al., 2018). Changing the conformation of proteins and increasing the relative proportion of β-sheets compared to the α-helices, which are dominant in proteins at the normal conditions, is a sign of the appearance of prion-like proteins.
Experiments elucidating the appearance of prion-like proteins in plants could shed the light to mitigate the severe consequences of prion diseases in offspreds. Since this approach allows us to identify proteins in the transition to a state with a high content of β-domain, they could also acquire allergenic properties, which is very relevant for the feeding of mammals suffered from a chronic wasting disease.