Phytaspase, a relocalisable cell death promoting plant protease with caspase specificity.
EMBO J
; 29(6): 1149-61, 2010 Mar 17.
Article
en En
| MEDLINE
| ID: mdl-20111004
ABSTRACT
Caspases are cysteine-dependent proteases and are important components of animal apoptosis. They introduce specific breaks after aspartate residues in a number of cellular proteins mediating programmed cell death (PCD). Plants encode only distant homologues of caspases, the metacaspases that are involved in PCD, but do not possess caspase-specific proteolytic activity. Nevertheless, plants do display caspase-like activities indicating that enzymes structurally distinct from classical caspases may operate as caspase-like proteases. Here, we report the identification and characterisation of a novel PCD-related subtilisin-like protease from tobacco and rice named phytaspase (plant aspartate-specific protease) that possesses caspase specificity distinct from that of other known caspase-like proteases. We provide evidence that phytaspase is synthesised as a proenzyme, which is autocatalytically processed to generate the mature enzyme. Overexpression and silencing of the phytaspase gene showed that phytaspase is essential for PCD-related responses to tobacco mosaic virus and abiotic stresses. Phytaspase is constitutively secreted into the apoplast before PCD, but unexpectedly is re-imported into the cell during PCD providing insights into how phytaspase operates.
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Péptido Hidrolasas
/
Proteínas de Plantas
/
Caspasas
Idioma:
En
Año:
2010
Tipo del documento:
Article