Tau protein binding forms a 1 nm thick layer along protofilaments without affecting the radial elasticity of microtubules

Iwan A. T. Schaap, Bernd Hoffmann, Carolina Carrasco, Rudolf Merkel, Christoph F. Schmidt

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

Tau is one of the most abundant microtubule-associated proteins involved in kinetic stabilization and bundling of axonal microtubules. Although intense research has revealed much about tau function and its involvement in Alzheimer's disease during the past years, it still remains unclear how exactly tau binds on microtubules and if the kinetic stabilization of microtubules by tau is accompanied, at least in part, by a mechanical reinforcement of microtubules. In this paper, we have used atomic force microscopy to address both aspects by visualizing and mechanically analyzing microtubules in the presence of native tau isoforms. We could show that tau at saturating concentrations forms a 1 nm thick layer around the microtubule, but leaves the protofilament structure well visible. The latter observation argues for tau binding mainly along and not across the protofilaments. The radial elasticity of microtubules was almost unaffected by tau, consistent with tau binding along the tops of the protofilaments. Tau did increase the resistance of microtubules against rupture. Finite-element calculations confirmed our findings.

Original languageEnglish
Pages (from-to)282-292
Number of pages11
JournalJournal of Structural Biology
Volume158
Issue number3
DOIs
Publication statusPublished - Jun 2007

Keywords

  • microtubule
  • tau protein
  • kinesin
  • atomic force microscopy
  • AFM
  • finite element modeling
  • FEM
  • SCANNING FORCE MICROSCOPY
  • 3-DIMENSIONAL STRUCTURE
  • CONVENTIONAL KINESIN
  • DYNAMIC INSTABILITY
  • MOLECULAR-STRUCTURE
  • RESOLUTION MODEL
  • TUBULIN
  • BRAIN
  • RIGIDITY
  • DOMAINS

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