MAP kinases function downstream of HSP90 and upstream of mitochondria in TMV resistance gene N-mediated hypersensitive cell death.
Plant Cell Physiol
; 48(3): 498-510, 2007 Mar.
Article
em En
| MEDLINE
| ID: mdl-17289794
ABSTRACT
Although the involvement of heat shock protein 90 (HSP90), mitogen-activated protein kinase (MAPK) cascades and organelle dysfunction in plant hypersensitive cell death has been suggested, the mutual relationship among them has not been elucidated. Here, we show the molecular network of HSP90, the wound-induced protein kinase (WIPK)/salicylic acid-induced protein kinase (SIPK)-mediated MAPK cascade and mitochondrial dysfunction in tobacco mosaic virus (TMV) resistance gene N-dependent cell death. p50, the Avr component for N, NtMEK2(DD), a constitutively active form of a MAPK kinase of WIPK/SIPK, and a mammalian pro-apoptotic factor Bax were used for cell death induction. Suppression of HSP90 and treatment with geldanamycin, a specific inhibitor of HSP90, compromised p50- but not NtMEK2(DD)- or Bax-mediated cell death accompanying the reduction of NtMEK2, WIPK and SIPK activation. In WIPK/SIPK-double knockdown plants, p50- and NtMEK2(DD)- but not Bax-mediated cell death was suppressed. All three types of cell death induced mitochondrial dysfunction, but they were similarly suppressed by Bcl-xL, which is a mammalian anti-apoptotic factor, and prevents mitochondrial dysfunction in plants as it does in animals in the cell death signal pathway. Taken together with the expression profile of hypersensitive reaction marker genes, it was indicated that the MAPK cascade functions downstream of HSP90 and transduces the cell death signal to mitochondria for N gene-dependent cell death. Furthermore, we found that WIPK and SIPK are functionally redundant in cell death signaling using WIPK/SIPK single or double knockdown plants.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Nicotiana
/
Vírus do Mosaico do Tabaco
/
Proteínas de Choque Térmico HSP90
/
Sistema de Sinalização das MAP Quinases
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Plant Cell Physiol
Ano de publicação:
2007
Tipo de documento:
Article