Differential association of tau with subsets of microtubules containing posttranslationally-modified tubulin variants in neuroblastoma cells

Lorena Saragoni, Paula Hernández, Ricardo B. Maccioni

Research output: Contribution to journalArticlepeer-review

33 Scopus citations

Abstract

Neuronal cells display different subsets of dynamic microtubules. In axons and extending neurites, this intrinsic dynamics is modulated by the microtubule-associated protein tau. Moreover, posttranslational modifications of tubulin, namely acetylation, tyrosination or glutamylation are directly involved in determining the stability of neuronal microtubules. Studies were carried out to analyze the interaction patterns of tau with subsets of microtubules in N2A neuroblastoma cells, which can differentiate in the presence of dibutyryl cAMP. Double labeling studies showed a differential pattern of tau association with microtubules containing acetylated and tyrosinated tubulin. Furthermore, studies using depolymerizing drugs revealed a selectivity in the association of tau with microtubular polymers and microfilaments, within the organization of the neuronal cytoskeleton. In order to study the association of specific tau isoforms with microtubules containing modified tubulin variants, immunoprecipitation studies were carried out. The coimmunoprecipitation data indicated a selective binding of specific tau isoforms to either modified tubulin variant. To assess the hypothesis on the roles of tau isoforms in the stabilization of microtubules containing modified tubulins, the association of those variants with tau isoforms was analyzed in overlay experiments. A preferential binding of acetylated tubulin from undifferentiated N2A cell extracts, to at least one slow-migrating tau isoform was revealed. However, acetylated tubulin from N2A cells containing long neurites displayed a preferential association with two isoforms of tau. On the other hand, tyrosinated tubulin from N2A extracts bound to the entire set of neuronal tau isoforms. These studies, along with the tau association with microtubules with different stability, indicate that tau segregates into subsets of microtubules in the axonal processes. The studies also suggest that these interactions may respond to a functional versatility of these polymers in differentiating neurons.

Original languageEnglish (US)
Pages (from-to)59-70
Number of pages12
JournalNeurochemical Research
Volume25
Issue number1
DOIs
StatePublished - 2000
Externally publishedYes

Keywords

  • Microtubule stability
  • Neuritogenesis
  • Neuroblastoma cells
  • Posttranslationally-modified tubulins
  • Tau proteins

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Differential association of tau with subsets of microtubules containing posttranslationally-modified tubulin variants in neuroblastoma cells'. Together they form a unique fingerprint.

Cite this