Tubulin-Na + , K + -ATPase interaction: Involvement in enzymatic regulation and cellular function

SANTANDER, VERONICA S.; CAMPETELLI, ALEXIS N.; MONESTEROLO, NOELIA E.; RIVELLI, JUAN F.; NIGRA, AYELEN D.; ARCE, CARLOS A.; CASALE, CÉSAR H.

JOURNAL OF CELLULAR PHYSIOLOGY

WILEY-LISS, DIV JOHN WILEY & SONS INC

Año: 2018

0021-9541

AbstractA new function for tubulin was described by our laboratory: acetylated tubulin formsa complex with Na+,K+‐ATPase (NKA) and inhibits its activity. This process was shownto be a regulatory factor of physiological importance in cultured cells, humanerythrocytes, and several rat tissues. Formation of the acetylated tubulin?NKAcomplex is reversible. We demonstrated that in cultured cells, high concentrations ofglucose induce translocation of acetylated tubulin from cytoplasm to plasmamembrane with a consequent inhibition of NKA activity. This effect is reversed byadding glutamate, which is coctransported to the cell with Na+. Another posttranslationalmodification of tubulin, detyrosinated tubulin, is also involved in the regulationof NKA activity: it enhances the NKA inhibition induced by acetylated tubulin.Manipulation of the content of these modifications of tubulin could work as a newstrategy to maintain homeostasis of Na+ and K+, and to regulate a variety of functionsin which NKA is involved, such as osmotic fragility and deformability of humanerythrocytes. The results summarized in this review show that the interactionbetween tubulin and NKA plays an important role in cellular physiology, both in theregulation of Na+/K+ homeostasis and in the rheological properties of the cells, whichis mechanically different from other roles reported up to now.