Differential axonal transport of soluble and insoluble τ in the rat sciatic nerve

Tomoko Tashiro, Xiaoyan Sun, Morihiro Tsuda, Yoshiaki Komiya

Research output: Contribution to journalArticle

12 Scopus citations

Abstract

Axonal transport of microtubule-associated protein τ was studied in the motor fibers of the rat sciatic nerve 1-4 weeks after labeling of the spinal cord with [35S]methionine. As 60-70% of low molecular weight τ in this system was found to be insoluble in 1% Triton-containing buffer, labeled proteins in 6-mm consecutive nerve segments were first separated into Triton- soluble and insoluble fractions. Two-dimensional gel electrophoresis and immunoblotting with anti-tau antibody confirmed the presence of τ among labeled, transported proteins in both fractions. Isoform composition of labeled τ was similar to that of bulk axonal τ, the most acidic species with apparent molecular mass of 66 kDa being the major component. Transport profiles obtained by measuring radioactivities associated with this major isoform showed that soluble and insoluble τ were transported at different rates. Insoluble τ, which contained the majority of τ-associated radioactivity, was transported at 1.7 mm/day in slow component a (SCa), whereas soluble τ was transported faster, at 3 mm/day, corresponding to the rate of slow component b (SCb). Cotransport of insoluble τ with insoluble tubulin in SCa suggests its association with stable microtubules.

Original languageEnglish (US)
Pages (from-to)1566-1574
Number of pages9
JournalJournal of Neurochemistry
Volume67
Issue number4
StatePublished - Oct 1996
Externally publishedYes

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Keywords

  • τ
  • τ protein
  • Axon
  • Axonal transport
  • Cytoskeleton
  • Microtubule

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

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