The slow axonal transport of the microtubule-associated protein tau and the transport rates of different isoforms and mutants in cultured neurons.
We demonstrate that the microtubule-associated protein tau, in the form of enhanced green fluorescent protein (EGFP) tau, is transported along axons of neurons in culture in the slow component of axonal transport with a speed comparable with that previously measured in vivo. It was demonstrated that the EGFP tag has no effect on transport characteristics, and the methodology enables slow transport rates of individual tau isoforms and tau mutants to be measured. We also expressed EGFP-tagged tau isoforms containing either three or four C-terminal repeats and zero or two N-terminal inserts in cultured neurons. No significant differences were found in the average rate of slow transport of the wild-type tau isoforms, suggesting that the exon 10 C-terminal repeat or the N-terminal inserts do not contain regions that play a significant regulatory role in axonal transport. Similarly, we found that missense mutations in tau have no noticeable effect on the rate of transport; hence their ability to cause neurodegeneration is by another mechanism other than that affecting the overall slow axonal transport of tau.
Utton
Michelle A
MA
Department of Neuroscience, Institute of Psychiatry, King's College London, London SE5 8AF, United Kingdom. m.utton@iop.kcl.ac.uk
Connell
James
J
Asuni
Ayodeji A
AA
van Slegtenhorst
Marjon
M
Hutton
Michael
M
de Silva
Rohan
R
Lees
Andrew J
AJ
Miller
Chris C J
CC
Anderton
Brian H
BH
D019943:Amino Acid Substitution; D000818:Animals; D001370:Axonal Transport / Q000187:drug effects / Q000502:physiology*; D001369:Axons / Q000378:metabolism; D002451:Cell Compartmentation; D002478:Cells, Cultured; D003847:Deoxyglucose / Q000494:pharmacology; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology; D005091:Exons; D008164:Luminescent Proteins / Q000235:genetics; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D016297:Mutagenesis, Site-Directed; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics; D019810:Sodium Azide / Q000494:pharmacology; D013329:Structure-Activity Relationship; D014162:Transfection; D016875:tau Proteins / Q000235:genetics / Q000378:metabolism*
D008164:Luminescent Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; D016875:tau Proteins; D019810:Sodium Azide; D003847:Deoxyglucose