Arabidopsis Bax Inhibitor-1 inhibits cell death induced by pokeweed antiviral protein in Saccharomyces cerevisae

Abstract

Apoptosis is an active form of programmed cell death (PCD) that plays critical roles in the development, differentiation and resistance to pathogens in multicellular organisms. Ribosome inactivating proteins (RIPs) are able to induce apoptotic cell death in mammalian cells. In this study, using yeast as a model system, we showed that yeast cells expressing pokeweed antiviral protein (PAP), a single-chain ribosome-inactivating protein, exhibit apoptotic-like features, such as nuclear fragmentation and ROS production. We studied the interaction between PAP and AtBI-1 (Arabidopsis thaliana Bax Inhibitor-1), a plant anti-apoptotic protein, which inhibits Bax induced cell death. Cells expressing PAP and AtBI-1 were able to survive on galactose media compared to PAP alone, indicating a reduction in the cytotoxicity of PAP in yeast. However, PAP was able to depurinate the ribosomes and to inhibit total translation in the presence of AtBI-1. A C-terminally deleted AtBI-1 was able to reduce the cytotoxicity of PAP. Since anti-apoptotic proteins form heterodimers to inhibit the biological activity of their partners, we used a co-immunoprecipitation assay to examine the binding of AtBI-1 to PAP. Both full length and C-terminal deleted AtBI-1 were capable of binding to PAP. These findings indicate that PAP induces cell death in yeast and AtBI-1 inhibits cell death induced by PAP without affecting ribosome depurination and translation inhibition.

Soybean Mosaic Virus 6K1 Interactors Screening and GmPR4 and GmBI1 Function Characterization

“…Previous studies have reported the roles of BI1 in biotic and abiotic stress. Bax inhibitor 1 (BI1) is a conserved ER protein, suppressing cell death in animals and plants and regulating a cell death pathway, which is important for cell preservation during ER stress [ 55 , 56 , 57 , 58 , 59 ]. AtBI1 was rapidly up-regulated during wounding and pathogen challenge and restricted Plantago asiatica mosaic virus (PlAMV) and Turnip mosaic virus (TuMV) infection in A. thaliana [ 60 , 61 , 62 ].…”

Genome-wide association study presents insights into the genetic architecture of drought tolerance in maize seedlings under field water-deficit conditions

“…The moderate content of ROS is considered to mediate the induction of defense pathways and help plants adapt to the changing environment ( Cruz de Carvalho, 2008 ). However, if stress continues to aggravate, the increase of ROS will lead to the damage of nucleic acids, proteins, lipids and other cellular components in plants, and causes programmed cell death (PCD) ( Çakır and Tumer, 2015 ). The conserved cell death suppressor Bax inhibitor-1 (BI-1) encoded by Zm00001d053952 plays a role in the downstream of PCD signaling and inhibits cell death.…”

Pokeweed Antiviral Protein: Its Cytotoxicity Mechanism and Applications in Plant Disease Resistance

“…Recent results showed that yeast cells expressing PAP exhibited apoptotic-like features, such as nuclear fragmentation and production of reactive oxygen species (ROS). Arabidopsis thaliana Bax inhibitor-1, a plant antiapoptotic protein, which inhibits Bax induced cell death reduced the cytotoxicity of PAP in yeast, without affecting ribosome depurination and translation inhibition [ 32 ]. These results provided further evidence that ribosome depurination and translation inhibition by PAP could be separated from cytotoxicity.…”