Amyloid-like protein inclusions in tobacco transgenic plants

The formation of insoluble protein deposits in human tissues is linked to the onset of more than 40 different disorders, ranging from dementia to diabetes. In these diseases, the proteins usually self-assemble into ordered β-sheet enriched aggregates known as amyloid fibrils. Here we study the structure of the inclusions formed by maize transglutaminase (TGZ) in the chloroplasts of tobacco transplastomic plants and demonstrate that they have an amyloid-like nature. Together with the evidence of amyloid structures in bacteria and fungi our data argue that amyloid formation is likely a ubiquitous process occurring across the different kingdoms of life. The discovery of amyloid conformations inside inclusions of genetically modified plants might have implications regarding their use for human applications.
This work was supported by grants BIO2007-68046, BFU2006-15115-CO2-01/BMC and BFU2009-08575 from Ministerio de Ciencia e Innovacion (Spain), by grant 2009-SGR 760 from AGAUR(Agencia de Gestio d'Ajuts Universitaris i de Recerca-Generalitat de Catalunya). AV was beneficiary of a PIF fellowship from Universidad Autonoma de Barcelona (UAB). RS was beneficiary of an I3 contract (UAB-Generalitat de Catalunya). JG was beneficiary of a FPI fellowship awarded by Generalitat de Catalunya. SV has been granted with an ICREA ACADEMIA award (ICREA-Institucio Catalana de Recerca i Estudis Avancats). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.