EFFECT OF CALCIUM ON THE DISTRIBUTION OF TUBULIN IN HUMAN ERYTHROCYTES

BALACH M.; MUHLBERGER T.; ELISIO Y.; SANTANDER V.; CASALE C; MONESTEROLO N.E

Buenos Aires

Congreso; SAIB 2017; 2017

SAIB

In previous work we demonstrated that tubulin is present in human erythrocytes and changes its distribution within the cell during arterial hypertension. In addition, we observe that erythrocyte deformability depends on the tubulin content in the membrane. On the other hand, tubulin regulates pmca activity depending on the lipid composition where the enzyme is immersed. Dag and pa activate pmca (decrease in intracellular calcium), causing a redistribution of tubulin in human erythrocytes, increasing the acetylated isotype content in the membrane. In this work we have proposed to study if variations in calcium concentration affect the distribution of tubulin in human erythrocytes and its relation to pmca activity. For this, the erythrocytes were incubated with different concentrations of calcium, in the presence and absence of a calcium ionophore (a23187) and also in the presence of caloxin different concentrations (specific inhibitor of pmca). Our immunofluorescence and western blot experiments demonstrate that intracellular calcium variation causes redistribution of tubulin in erythrocytes. At high concentrations of calcium the tubulin migrates to the membrane and this causes a decrease in its deformability, reaching values similar to those found during arterial hypertension. Therefore, we conclude that the inhibition of pmcaand the consequent increase of calcium concentration during hypertension are implicated in the migration of tubulin to the membrane, causing a decrease in erythrocyte deformability that contributes to the increase of blood pressure.