Zubčić K, Franić D, Pravica M, Hof PR, Šimić G, Boban M. Effects of heterologous human tau protein expression in yeast models of proteotoxic stress response.
CNS Neurosci Ther 2024;
30:e14304. [PMID:
37341072 PMCID:
PMC11163194 DOI:
10.1111/cns.14304]
[Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/23/2023] [Accepted: 05/24/2023] [Indexed: 06/22/2023] Open
Abstract
BACKGROUND
The primary histological characteristic of Alzheimer's disease is the presence of neurofibrillary tangles, which are large aggregates of tau protein. Aging is the primary risk factor for the development of Alzheimer's disease, however, the underlying causes of tau protein aggregation and toxicity are unclear.
AIMS
Here we investigated tau aggregation and toxicity under the conditions of compromised protein homeostasis.
METHODS
We used heterologous expression of human tau protein in the unicellular eukaryote yeast Saccharomyces cerevisiae with evolutionarily conserved protein quality control pathways and examined tau-dependent toxicity and aggregation using growth assays, fluorescence microscopy, and a split luciferase-based reporter NanoBiT.
RESULTS
Tau protein expressed in yeast under mild proteotoxic stress, or in mutants with impaired pathways for proteotoxic stress response, did not lead to synthetic toxicity or the formation of obvious aggregates. Chronologically old cells also did not develop observable tau aggregates. Our examination of tau oligomerization in living cells using NanoBiT reporter suggests that tau does not form significant levels of oligomers under basal conditions or under mild proteotoxic stress.
CONCLUSION
Together our data suggest that human tau protein does not represent a major burden to the protein quality control system in yeast cells.
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