HSP90 and checkpoint-dependent lengthening of the G2 phase observed in plant cells under hypoxia and cold.
Protoplasma
; 223(2-4): 191-6, 2004 Jun.
Article
en En
| MEDLINE
| ID: mdl-15221524
ABSTRACT
Proliferating cells of Allium cepa L. roots became adapted to hypoxia (5% oxygen) and cold (10 degrees C) by acquiring new steady-state kinetics of growth. The cell cycle time increased from the 17.6 h in control meristems up to 29.7 and 69.0 h under hypoxia and cold conditions, respectively. Acclimation of the proliferating cells was stress specific. No acclimation took place after 24 h of heat treatment (40 degrees C). Under cold treatment, all cycle phases enlarged uniformly. However, under hypoxia, while the G(1) and S cycle phases roughly doubled in their timing, the expected checkpoint-dependent lengthening of G(2) did not take place. This failure in lengthening G(2) in response to hypoxia correlated with a failure in the overinduction of a single peptide with a molecular mass of about 134 kDa which is among those recognised by an HSP90 antibody. Moreover, the presence of this large peptide of the HSP90 family proved to be a marker for cell proliferation. It was always absent from the contiguous differentiated cells of the root. Lastly, the mitochondrial chaperonin recognized by an HSP60 antibody in these roots not involved in photosynthesis was always higher in the proliferating than in the nonproliferating cells.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fase G2
/
Frío
/
Proteínas HSP90 de Choque Térmico
/
Cebollas
Idioma:
En
Revista:
Protoplasma
Asunto de la revista:
BIOLOGIA
Año:
2004
Tipo del documento:
Article
País de afiliación:
España