title: The proteome response to amyloid protein expression in vivo.
abstract: Protein misfolding disorders such as Alzheimer, Parkinson and transthyretin amyloidosis are characterized by the formation of protein amyloid deposits. Although the nature and location of the aggregated proteins varies between different diseases, they all share similar molecular pathways of protein unfolding, aggregation and amyloid deposition. Most effects of these proteins are likely to occur at the proteome level, a virtually unexplored reality. To investigate the effects of an amyloid protein expression on the cellular proteome, we created a yeast expression system using human transthyretin (TTR) as a model amyloidogenic protein. We used Saccharomyces cerevisiae, a living test tube, to express native TTR (non-amyloidogenic) and the amyloidogenic TTR variant L55P, the later forming aggregates when expressed in yeast. Differential proteome changes were quantitatively analyzed by 2D-differential in gel electrophoresis (2D-DIGE). We show that the expression of the amyloidogenic TTR-L55P causes a metabolic shift towards energy production, increased superoxide dismutase expression as well as of several molecular chaperones involved in protein refolding. Among these chaperones, members of the HSP70 family and the peptidyl-prolyl-cis-trans isomerase (PPIase) were identified. The latter is highly relevant considering that it was previously found to be a TTR interacting partner in the plasma of ATTR patients but not in healthy or asymptomatic subjects. The small ubiquitin-like modifier (SUMO) expression is also increased. Our findings suggest that refolding and degradation pathways are activated, causing an increased demand of energetic resources, thus the metabolic shift. Additionally, oxidative stress appears to be a consequence of the amyloidogenic process, posing an enhanced threat to cell survival.
authors.affiliation: Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
authors.forename: Ricardo A
authors.initials: RA
authors.lastname: Gomes
authors.forename: Catarina
authors.initials: C
authors.lastname: Franco
authors.forename: Gonçalo
authors.initials: G
authors.lastname: Da Costa
authors.forename: Sébastien
authors.initials: S
authors.lastname: Planchon
authors.forename: Jenny
authors.initials: J
authors.lastname: Renaut
authors.forename: Raquel M
authors.initials: RM
authors.lastname: Ribeiro
authors.forename: Francisco
authors.initials: F
authors.lastname: Pinto
authors.forename: Marta Sousa
authors.initials: MS
authors.lastname: Silva
authors.forename: Ana Varela
authors.initials: AV
authors.lastname: Coelho
authors.forename: Ana Ponces
authors.initials: AP
authors.lastname: Freire
authors.forename: Carlos
authors.initials: C
authors.lastname: Cordeiro
mesh_terms: D058227:Amyloidogenic Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D053858:Metabolic Networks and Pathways; D008958:Models, Molecular; D019696:Peptidylprolyl Isomerase / Q000235:genetics / Q000378:metabolism; D011228:Prealbumin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D011487:Protein Conformation; D011489:Protein Denaturation; D058849:Protein Refolding; D020543:Proteome / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic; D057825:Two-Dimensional Difference Gel Electrophoresis
chemical_list: D058227:Amyloidogenic Proteins; D018840:HSP70 Heat-Shock Proteins; D011228:Prealbumin; D020543:Proteome; D029701:Saccharomyces cerevisiae Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; D019696:Peptidylprolyl Isomerase