Premium
Understanding the nature of toxicity of Parkinson's disease associated alpha‐synuclein familial mutants H50Q, G51D, and A53E with yeast models
Author(s) -
Ong Emily Nicole,
Tembo Maiwase,
Mwale Chisomo,
Marshall Morgan,
Alvarado Charles,
Buabeng Michael,
Kukulka Natalie,
DebBurman Shubhik
Publication year - 2017
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.31.1_supplement.lb100
Subject(s) - mutant , alpha synuclein , yeast , amino acid , mutation , biology , saccharomyces cerevisiae , biochemistry , microbiology and biotechnology , genetics , gene , parkinson's disease , chemistry , disease , medicine , pathology
Parkinson's disease (PD) is associated with the aggregation and misfolding of alpha‐synuclein in midbrain dopaminergic neurons. The gene for alpha‐synuclein has six known mutations that directly cause familial forms of PD. The pathological determinants of three of these mutants (A30P, E46K, and A53T) are well characterized in diverse model systems and they that reveal that each mutant affects cellular toxicity in distinctive ways. The three more recently discovered familial mutants (H50Q, G51D, and A53E) are not extensively studied. We expressed H50Q, G51D, and A53E mutants in budding and fission yeasts model systems and hypothesized that each would generate toxicity by altering their membrane association and aggregation properties, and by disrupting cellular pathways including nitrative stress responses and endocytosis, but each would do so in distinctive ways. First, we found that the H50Q and A53E mutants were toxic to yeast, and bound membranes and aggregated within yeast, while G51D was cytoplasmically diffuse and nontoxic. Secondly, and surprisingly, we found that G51D mutant dominated over H50Q and A53E when these mutants were combined in double/triple mutants. Thirdly, we asked whether the loss of the original amino acid or the gain of the new amino acid in each new familial mutant is responsible for disease. We created four substitution mutations for H50Q, G51D, and A53E in both yeasts models corresponding to the four functional classes of amino acids. We found that H50D was cytoplasmically diffuse and nontoxic, G51A bound membranes and aggregated like WT, G51E was cytoplasmically diffuse and nontoxic like G51D, and A53R was cytoplasmically diffuse and nontoxic, suggesting both the loss of the original amino acid and the gain of the new amino acid are key. Finally, we are currently characterizing these familial mutants in yeast strains altered for endocytosis, nitrative stress, and sumoylation. Collectively, this work adds insight into the pathogenicity of different familial PD mutants of alpha‐synuclein. Support or Funding Information E.O. was funded by Parkinson's Disease Foundation