Distinct isoforms of ADPglucose pyrophosphatase and ADPglucose pyrophosphorylase occur in the suspension‐cultured cells of sycamore (Acer pseudoplatanus L.)

FEBS Letters

Akazawa, Takashi¹  Baroja-Fernández, Edurne¹  Pozueta-Romero, Javier¹  Zandueta-Criado, Aitor¹  Rodrı́guez-López, Milagros¹ 

[1] Instituto de Agrobiotecnologı́a y Recursos Naturales, Universidad Pública de Navarra/Consejo Superior Investigaciones Cientı́ficas, Ctra. Mutilva s/n, 31192 Mutilva Baja, Navarra, Spain

关键词: Amyloplast;    Gluconeogenesis;    Phosphodiesterase;    Starch;    ADH;    alcohol dehydrogenase;    ADPG;    ADPglucose;    AGPase;    ADPG pyrophosphorylase;    AGPPase;    ADPG pyrophosphatase (or ADPG phosphodiesterase);    G1P;    glucose 1-phosphate;    6PGDH;    6-phosphogluconate dehydrogenase;    NiR;    nitrite reductase;    PFK(PPi);    pyrophosphate–fructose-6-phosphate 1 phosphotransferase;    PPase;    alkaline pyrophosphatase;    SS;    sucrose synthase;    TPI;    triose-P-isomerase;    UGPase;    UDPglucose pyrophosphorylase;   

DOI  :  10.1016/S0014-5793(00)01951-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The intracellular localizations of ADPglucose pyrophosphatase (AGPPase) and ADPglucose pyrophosphorylase (AGPase) have been studied using protoplasts prepared from suspension-cultured cells of sycamore (Acer pseudoplatanus L.). Subcellular fractionation studies revealed that all the AGPPase present in the protoplasts is associated with amyloplasts, whereas more than 60% of AGPase is in the extraplastidial compartment. Immunoblots of amyloplast- and extraplastid-enriched extracts further confirmed that AGPase is located mainly outside the amyloplast. Experiments carried out to identify possible different isoforms of AGPPase in the amyloplast revealed the presence of soluble and starch granule-bound isoforms. We thus propose that ADPglucose levels linked to starch biosynthesis in sycamore cells are controlled by enzymatic reactions catalyzing the synthesis and breakdown of ADPglucose, which take place both inside and outside the amyloplast.

【 授权许可】

Unknown