Pyruvate kinase as a microtubule destabilizing factor in vitro

Biochem Biophys Res Commun. 1999 Jan 19;254(2):430-5. doi: 10.1006/bbrc.1998.9957.


Endogenous control of microtubule dynamism is essential in many cell types. Numerous microtubule-adhering proteins stabilize the polymer status, while very few protein factors are described with opposite effects. The brain- and muscle-specific M1 isoform of the enzyme pyruvate kinase is investigated here in this respect. Three pieces of evidence indicate antimicrotubular effects of this protein. (1) Pyruvate kinase inhibits taxol-induced tubulin polymerization into microtubules as revealed by turbidimetry. (2) Pelleting experiments show that pyruvate kinase partially disassembles taxol-stabilized microtubules into less sedimentable oligomers leading to the appearance of tubulin in the supernatant fractions. (3) Electron microscopy reveals the kinase-induced formation of great amounts of thread-like tubulin oligomers which tend to accumulate in a light/less sedimentable fraction. Immunoelectron micrographs using labeled antibody against pyruvate kinase provide evidence for the binding of pyruvate kinase to the thread-like oligomeric forms. The present data allow the assumption that pyruvate kinase may display multiple regulatory functions as a glycolytic control enzyme and as a modulator of microtubule dynamism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Brain / metabolism
  • Cattle
  • Kinetics
  • Macromolecular Substances
  • Microtubules / metabolism*
  • Microtubules / ultrastructure*
  • Muscle, Skeletal / enzymology*
  • Pyruvate Kinase / metabolism*
  • Rabbits
  • Tubulin / isolation & purification
  • Tubulin / metabolism*


  • Macromolecular Substances
  • Tubulin
  • Pyruvate Kinase