INVESTIGADORES
ADAMO hugo Pedro
congresos y reuniones científicas
Título:
The effect of P5-ATPases and spermidine on the proliferation of S. cerevisiae
Autor/es:
SELLES MARIA CLARA; SARBIA NICOLAS; ADAMO HUGO PEDRO; CORRADI GERARDO RAUL
Lugar:
San Javier, Tucuman
Reunión:
Encuentro; XLI Reunion de la Sociedad Argentina de Biofisica; 2012
Institución organizadora:
Sociedad Argentina de Biofisica
Resumen:
The effect of
P5-ATPases and spermidine on the proliferation of S. cerevisiae.
RESERVADO SAB
María Clara Sellés, Nicolás Sarbia,
Hugo P. Adamo and Gerardo R. Corradi
IQUIFIB-Facultad
de Farmacia y
Bioquímica, Universidad de
Buenos Aires, Junín
956, 1113, Buenos
Aires, Argentina.
P-type ATPases comprise a large family of proteins, present
in prokaryotic as well as in eukaryotic cells, which catalyze active transport
of inorganic cations and other substrates through cell membranes. They have
been divided into five sub-families named P1-P5 according to their sequence
similarities. The least studied one is the P5-ATPase sub-family which is only
expressed in eukaryotes. The yeast Saccharomyces
cerevisiae is an inferior eukaryote and it contains two genes that code for
P5-ATPases: Yel031w codes for the Spf1 protein or Cod1p, which corresponds to
the group of P5A-ATPases; and Yor291w encode Ypk9 protein, which belongs to the
P5B-ATPases group. The substrate transported by this sub-family of P-type
ATPases is still unknown although it has been shown that their activity
modifies cellular uptake of polyamines, such as spermidine. In this study, we
investigated the effect of the inactivation of the genes that encode SPF1 and
YPK9 in S. cerevisiae and the overexpression of SPF1 regarding cellular
proliferation under stress conditions and in the presence of the polycation
spermidine.
At 28 C in YPD medium, the OD of the wild type culture
reached a maximal value in about 10 days. A similar growth curve was observed
for the ΔSpf1 and ΔYpk9 strains. However when treated with 4 mM spermidine for
24 hours, an OD 20-40% higher was reached by the wild type and ΔSpf1 while ΔYpk9
was not affected. The ΔSpf1 strain was transformed with a vector coding for Spf1
or a mutant Spf1D487N (devoid of ATPase activity) both fused to GFP. In SC
medium (without Leu) the yeasts containing the active protein grew much better
than those transformed with Spf1D487N. The incubation in water for 24 hours with
10mM spermidine increased the GFP fluorescence. Altoghether, these results
suggest that the YPK9 is necessary for the stimulating effect of spermidine and
that overexpression of a functional Spf1 increases proliferation.