INVESTIGADORES
ROSSI juan pablo Francisco
congresos y reuniones científicas
Título:
Divalent metal ions transport by Plasma Membrane Calcium ATPase. Effect on regulation and selectivity
Autor/es:
ONTIVEROS, MQ., MANGIALAVORI, IC., MARTIARENA, J., ROSSI, JPFC. AND FERREIRA GOMES, MS
Lugar:
Villa Carlos Paz, Córdoba
Reunión:
Congreso; ? XLII. Reunión Anual de la Sociedad Argentina de Biofísica (SAB).; 2013
Institución organizadora:
SAB
Resumen:
Divalent
metal ions transport by Plasma Membrane Calcium ATPase. Effect on regulation
and selectivity.
Ontiveros, MQ; Mangialavori, I; Martiarena, J; Rossi, JP, Ferreira‑Gomes,
MS
Instituto de Química
y Fisicoquímica Biológicas y Departamento de Química Biológica Dr. Paladini. Universidad de Buenos Aires
The plasma membrane calcium pump(PMCA) transports Ca2+ actively to the extracellular medium
coupled to the ATP hydrolysis maintaining the cellular homeostasis. PMCA is
activated by interaction with Ca2+-calmodulin complex or by acidic
phospholipids, increasing its affinity for Ca2+ and its maximum velocity
[1, 2]. The aim of this work was to study the transport of different divalent
cations that could be transported by PMCA, the effect on calmodulin regulation
and the selectivity of the pump. We assay the
alkaline metals Be2+, Ca2+, Sr2+ and Ba2+,
and Co2+, Cd2+ and Pb2+ from the
fourth, fifth and sixth periods. The experiments were performed with both IOVs
and the purified enzyme isolated from membranes of human erythrocytes. Results show
that: (a) PMCA is able to transport Ca2+, Sr2+, Ba2+,
Co2+ and Pb2+ with different capacity and
affinity while Be2+ and Cd2+ are
not transported; (b) PMCA activated by calmodulin shows an
increased affinity for those cations; (c) there is a
relation between the ionic radii of cations and the transport capability of the
pump.
These results suggest that the
mechanism of expulsion of Ca2+ mediated by PMCA would also transport
other divalent cations and that the size of such cation must be optimal for the
interaction with the binding site of the enzyme.
With grants of ANPCYT, CONICET and UBACYT
1- Mangialavori y col. J Biol Chem. 2009. 4823
2- Filomatoriy col. J Biol Chem. 2003. 22265