INIMEC - CONICET   05467
INSTITUTO DE INVESTIGACION MEDICA MERCEDES Y MARTIN FERREYRA
Unidad Ejecutora - UE
artículos
Título:
Optimal metabolic regulation of the mammalian heart Na+/Ca2+ exchanger
Autor/es:
DIEGO FORCATO; VELIA POSADA; LUIS BEAUGÉ; : GRACIELA ELSO DE BERBERIAN
Revista:
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
Editorial:
ACADEMIC PRESS INC ELSEVIER SCIENCE
Referencias:
Año: 2010 vol. 402 p. 147 - 152
ISSN:
0006-291X
Resumen:
In inside-out bovine heart sarcolemmal vesicles, p-chloromercuribenzenesulfonate (PCMBS) and n-ethylmaleimide
(NEM) fully inhibited MgATP up-regulation of the Na+/Ca2+ exchanger (NCX1) and abolished
the MgATP-dependent PtdIns-4,5P2 increase in the NCX1PtdIns-4,5P2 complex; in addition, these compounds
markedly reduced the activity of the PtdIns(4)-5kinase. After PCMBS or NEM treatment, addition
of dithiothreitol (DTT) restored a large fraction of the MgATP stimulation of the exchange fluxes and
almost fully restored PtdIns(4)-5kinase activity; however, in contrast to PCMBS, the effects of NEM did
not seem related to the alkylation of protein SH groups. By itself DTT had no effect on the synthesis of
PtdIns-4,5P2 but affected MgATP stimulation of NCX1: moderate inhibition at 1 mM MgATP and 1 lM
Ca2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
Ca2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
the MgATP-dependent PtdIns-4,5P2 increase in the NCX1PtdIns-4,5P2 complex; in addition, these compounds
markedly reduced the activity of the PtdIns(4)-5kinase. After PCMBS or NEM treatment, addition
of dithiothreitol (DTT) restored a large fraction of the MgATP stimulation of the exchange fluxes and
almost fully restored PtdIns(4)-5kinase activity; however, in contrast to PCMBS, the effects of NEM did
not seem related to the alkylation of protein SH groups. By itself DTT had no effect on the synthesis of
PtdIns-4,5P2 but affected MgATP stimulation of NCX1: moderate inhibition at 1 mM MgATP and 1 lM
Ca2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
Ca2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
+/Ca2+ exchanger (NCX1) and abolished
the MgATP-dependent PtdIns-4,5P2 increase in the NCX1PtdIns-4,5P2 complex; in addition, these compounds
markedly reduced the activity of the PtdIns(4)-5kinase. After PCMBS or NEM treatment, addition
of dithiothreitol (DTT) restored a large fraction of the MgATP stimulation of the exchange fluxes and
almost fully restored PtdIns(4)-5kinase activity; however, in contrast to PCMBS, the effects of NEM did
not seem related to the alkylation of protein SH groups. By itself DTT had no effect on the synthesis of
PtdIns-4,5P2 but affected MgATP stimulation of NCX1: moderate inhibition at 1 mM MgATP and 1 lM
Ca2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
Ca2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
lM
Ca2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.
2+ and full inhibition at 0.25 mM MgATP and 0.2 lM Ca2+. In addition, DDT prevented coimmunoprecipitation
of NCX1 and PtdIns(4)-5kinase. These results indicate that, for a proper MgATP up-regulation of
NCX1, the enzyme responsible for PtdIns-4,5P2 synthesis must be (i) functionally competent and (ii) set
in the NCX1 microenvironment closely associated to the exchanger. This kind of supramolecular structure
is needed to optimize binding of the newly synthesized PtdIns-4,5P2 to its target region in the
exchanger protein.