Interaction between Tubulin and Na⁺,K⁺-ATPase in Brain Stem Neurons

N. M. Vladimirova^*, E. N. Sautkina, T. V. Ovchinnikova, and N. A. Potapenko

Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, Moscow, 117997 Russia; fax: (095) 336-4444; E-mail: vla@mail.ibch.ru

^* To whom correspondence should be addressed.

Received November 8, 2001; Revision received December 5, 2001

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Functionally active Na⁺,K⁺-ATPase isozymes containing three types of the catalytic subunits (alpha1, alpha2, and alpha3) were obtained from calf brain by two methods: selective removal of contaminating proteins according to Jorgensen (1974) and selective solubilization of the enzyme with subsequent reformation of the membrane structure according to Esmann (1988). All preparations were characterized with respect to ouabain-inhibition constants. The presence of the cytoskeleton protein tubulin (beta3 isoform) in the high-molecular-weight complex of Na⁺,K⁺-ATPase alpha3beta1 isozyme from brain stem axolemma and the junction between Na⁺,K⁺-ATPase alpha3 subunit and tubulin beta3 subunit are shown for the first time.

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KEY WORDS: Na⁺,K⁺-ATPase, isoforms, isozymes, axolemma, tubulin

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