Expression of an altered form of tau in Sf9 insect cells results in the assembly of polymers resembling Alzheimer's paired helical filaments.
Tau is the main component of the paired helical filaments (PHFs), aberrant structures that develop in the brain of Alzheimer's disease (AD) patients and other tauopathies like frontotemporal dementia and parkinsonism associated to chromosome 17 (FTDP-17). Previous work has shown that tau overexpression in Sf9 insect cells results in the formation of long cytoplasmatic extensions as a consequence of microtubule stabilization and bundling. Throughout this work, we have taken studies in this system further by overexpression of an altered form of tau characteristic of FTDP-17, which includes three mutations (G272V, P301L and R406W) and biochemically behaves as a hyperphosphorylated form of the protein, with the aim of developing an in vitro model which would favour the formation of tau aggregates. Our results indicate that filaments resembling PHFs assemble when Sf9 cells overexpress FTDP-17 tau. The amount of these polymers is reduced in lithium treated cells which suggests that phosphorylation of FTDP-17 tau by GSK3 induces a conformational change favouring the formation of fibrillar polymers.
Gómez-Ramos
Alberto
A
Centro de Biología Molecular (CSIC/UAM), Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
Abad
Xabier
X
López Fanarraga
Mónica
M
Bhat
Ratan
R
Zabala
Juan Carlos
JC
Avila
Jesús
J
D008841:Actin Cytoskeleton / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D000544:Alzheimer Disease / Q000378:metabolism*; D000818:Animals; D016367:Baculoviridae; D015153:Blotting, Western / Q000379:methods; D002460:Cell Line / Q000187:drug effects / Q000648:ultrastructure / Q000821:virology; D005260:Female; D005455:Fluorescent Antibody Technique / Q000379:methods; D005786:Gene Expression Regulation; D006801:Humans; D007313:Insecta; D008094:Lithium / Q000494:pharmacology; D016253:Microscopy, Immunoelectron / Q000379:methods; D008869:Microtubule-Associated Proteins; D008870:Microtubules / Q000187:drug effects / Q000648:ultrastructure; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D016874:Neurofibrillary Tangles / Q000187:drug effects / Q000648:ultrastructure; D010053:Ovary; D010766:Phosphorylation / Q000187:drug effects; D014162:Transfection / Q000379:methods; D016875:tau Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure
C054369:MAPT protein, human; D008869:Microtubule-Associated Proteins; D016875:tau Proteins; D008094:Lithium