INVESTIGADORES
ROSSI juan pablo Francisco
congresos y reuniones científicas
Título:
¨Plasma Membrane Calcium Pump regulation by the Cytoskeleton¨
Autor/es:
VANAGAS, L.; MANGIALAVORI IRENE; ROLANDO ROSSI; ROSSI, J.P.F.C.
Lugar:
MONTEVIDEO, URUGUAY
Reunión:
Congreso; 34th Annual Meeting of the Argentine Biophysical Society; 2007
Institución organizadora:
SOCIEDAD ARGENTINA DE BIOFISICA
Resumen:
¨Plasma Membrane Calcium Pump regulation by the Cytoskeleton¨. SAB Vol 34. p 118.
Vanagas.L., Mangialavori, IC., Rossi, RC. And Rossi, JPFC
When we measure the specific activity of the
PMCA in isolated red blood cell membranes as a function of the protein
concentration, the specific activity is not constant but it presents an
activation-inhibition behavior. We call this effect the ¨dilution phenomenon¨.
When we modified the cytoskeleton of actin with cytochalasin D, we found that
the activation-inhibition behavior could be assigned to the interaction between
PMCA and actin. These preliminary results allowed us to raise the hypothesis
that the phenomenon of activation-inhibition of the specific activity of PMCA
could be assigned to its interaction with the cytoskeleton proteins, which
according to their state would modify the activity of calcium transport.
Results in this paper show that: (1) monomeric
or G actin produces the activation of PMCA; (2) filamentous or F actin produces
the inhibition of PMCA. Such results were also observed measuring the
phosphorylation of the enzyme and the transport of calcium. (3) The effects of
actin on PMCA are the expression of the direct interaction of the enzyme with
actin. (4) The dilution phenomenon seems to be a general property of membrane
proteins in which the underlying cytoskeleton could be a regulator of the
enzymatic activity.