IIB   20738
INSTITUTO DE INVESTIGACIONES BIOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Caspase- 3 like activity in Solanum tuberosum-P. infestans interaction
Autor/es:
FERNÁNDEZ, MB; DALEO, GR; GUEVARA, MG
Reunión:
Congreso; XLVI Reunión anual-Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2010
Resumen:
Caspases are key components in animal programmed cell death. In the last decade, caspase like activities were described during different plant developmental and defense responses. Here we present a new plant- pathogen system where caspase-3 like activity was detected. Protein extracts from Solanum tuberosum leaves infected with Phytophthora infestans for 0, 1, 6, 12, 24 and 48hs were prepared. Greater relative DEVDase activity was detected at pH 5,2 and 37ºC after 24 h of P. infestans infection. This activity was significantly inhibited (85%) when extracts were pre- incubated for 1 h with specific DEVDase inhibitor (Ac-DEVD-CHO 50 µM). General protease and caspase inhibitors had no effect (2,5 mM PMSF, 100 µM E-64, 10 µM E-64, 0,5 mM Pepstatin A and 50 µM Z-VAD-FMK). An in silico prediction analysis of potential caspase- like cleavage site (DEVD) restricted to S. tuberosum revealed 7 predicted proteins in GenPep, 16 in TrEMBL and 1 in Swiss Prot databases with at least one DEVD motif. Most of these proteins correspond to apoptosis related proteins and transcription factors. Finally, this DEVDase activity appears to be related to animal caspases, since it is insensitive to broad- range general protease inhibitors. However, in contrast to animal caspase 3 which is active at pH 7, DEVDase activity was active at acidic pH, possibly suggesting a vacuolar or mitochondrial localization.