ADP-Glucose Pyrophosphorylase Is Located in the Plastid in Developing Tomato Fruit1

AUTOR(ES)

Beckles, Diane M.

FONTE

American Society of Plant Physiologists

RESUMO

The subcellular location of activity and protein of ADP-glucose pyrophosphorylase (AGPase) in developing tomato (Lycopersicon esculentum) fruit was determined following a report that the enzyme might be present inside and outside the plastids in this organ. Plastids prepared from crude homogenates of columella and pericarp, the starch-accumulating tissues of developing fruit, contained 8% to 18% of the total activity of enzymes known to be confined to plastids, and 0.2% to 0.5% of the total activity of enzymes known to be confined to the cytosol. The proportion of the total activity of AGPase in the plastids was the same as that of the enzymes known to be confined to the plastid. When samples of plastid and total homogenate fractions were subjected to immunoblotting with an antiserum raised to AGPase, most or all of the protein detected was plastidial. Taken as a whole, these data provide strong evidence that AGPase is confined to the plastids in developing tomato fruit.

Documentos Relacionados

• ADP-Glucose Pyrophosphorylase Is Localized to Both the Cytoplasm and Plastids in Developing Pericarp of Tomato Fruit1
• Multiple forms of ADP-glucose pyrophosphorylase from tomato fruit.
• Both Subunits of ADP-Glucose Pyrophosphorylase Are Regulatory1
• The Allosterically Unregulated Isoform of ADP-Glucose Pyrophosphorylase from Barley Endosperm Is the Most Likely Source of ADP-Glucose Incorporated into Endosperm Starch1
• Directed molecular evolution of ADP-glucose pyrophosphorylase