Artículo
Ultrasensitive behavior in the synthesis of storage polysaccharides in cyanobacteria
Fecha de publicación:
04/2003
Editorial:
Springer
Revista:
Planta
ISSN:
0032-0935
e-ISSN:
1432-2048
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The glycogen synthetic pathway operates ultrasensitively as a function of the ADPglucose pyrophosphorylase (ADPGlcPPase) allosteric effectors, 3-phosphoglycerate and Pi, in permeabilized cells of the cyanobacterium Anabaena PCC 7120. In vitro data previously showed that the ultrasensitive behavior of ADPGlcPPase depends upon cross-talk between the two allosteric effectors, the enzyme's response being additionally modulated by molecular crowding [D.F. Gómez Casatiet al. (2000) Biochem J 350:139–147]. In the present work we show, experimentally and with a mathematical model, that α-1,4-glucan synthesis is also ultrasensitive in cells due to the propagation of the switch-like behavior of ADPGlcPPase to the synthetic pathway. Amplifications of up to 20-fold in storage-polysaccharide synthesis can be achieved with a modest 6.7-fold increase in 3-phosphoglycerate in the presence of 5 mM Pi in contrast to the 30-fold necessary in its absence. This is the first time that this phenomenon has been reported to occur in the glycogen synthetic pathway of a photosynthetic prokaryote. The implications of the results for plant cell physiology during light–dark transitions are discussed.
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Articulos(IAL)
Articulos de INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Articulos de INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Articulos(IIB-INTECH)
Articulos de INST.DE INVEST.BIOTECNOLOGICAS - INSTITUTO TECNOLOGICO CHASCOMUS
Articulos de INST.DE INVEST.BIOTECNOLOGICAS - INSTITUTO TECNOLOGICO CHASCOMUS
Citación
Gomez Casati, Diego Fabian; Cortassa, Sonia del Carmen; Aon, Miguel A.; Iglesias, Alberto Alvaro; Ultrasensitive behavior in the synthesis of storage polysaccharides in cyanobacteria; Springer; Planta; 216; 6; 4-2003; 969-975
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