N-rich protein (NRP)-mediated cell death signaling: a new branch of the ER stress response with implications for plant biotechnology

• Autor(a) principal: Reis, Pedro A.B.
• Data de Publicação: 2012
• Outros Autores: Fontes, Elizabeth P.B.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://dx.doi.org/10.4161/psb.20111; http://www.locus.ufv.br/handle/123456789/19185
• topic: Endoplasmic reticulum stress; Osmotic stress; Cell death response; N-rich proteins; GmNAC6; ERD15; NRP-A; NRP-B

Upon disruption of ER homeostasis, plant cells activate at least two branches of the unfolded protein response (UPR) through IRE1-like and ATAF6-like transducers, resulting in the upregulation of ER-resident molecular chaperones and the activation of the ER-associated degradation protein system. Here, we discuss a new ER stress response pathway in plants that is associated with an osmotic stress response in transducing a cell death signal. Both ER and osmotic stress induce the expression of the novel transcription factor GmERD15, which binds and activates N-rich protein (NRP) promoters to induce NRP expression and cause the upregulation of GmNAC6, an effector of the cell death response. In contrast to this activation mechanism, the ER-resident molecular chaperone binding protein (BiP) attenuates the propagation of the cell death signal by modulating the expression and activity of components of the ER and osmotic stress-induced NRP-mediated cell death signaling. This interaction attenuates dehydration-induced cell death and promotes a better adaptation of BiP-overexpressing transgenic lines to drought.