Open AccessPhosphorylation of sucrose synthase from maize seedlings.
Author(s) -
Susanne Lindblom,
Pia Ek,
Grażyna Muszyńska,
Bo Ek,
Jadwiga Szczegielniak,
Lorentz Engström
Publication year - 1997
Publication title -
acta biochimica polonica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.452
H-Index - 78
eISSN - 1734-154X
pISSN - 0001-527X
DOI - 10.18388/abp.1997_4386
Subject(s) - biochemistry , sucrose synthase , protein kinase a , phosphorylation , enzyme , kinase , protein phosphorylation , atp synthase , biology , chemistry , invertase
Two isoforms of sucrose synthase (SS1 and SS2) from maize (Zea mays, var. Mona) seedlings co-purified with a calcium and phospholipid dependent protein kinase. The enzymatic preparation obtained gave a positive reaction with the antibody against mammalian protein kinase C. Maize sucrose synthase was phosphorylated by the endogenous protein kinase. Also, mammalian protein kinases (protein kinase C and protein kinase A) were able to phosphorylate the 86 kDa subunit of sucrose synthase. When excised seedlings were fed [32P]orthophosphate, sucrose synthase was also phosphorylated. Microsequencing of in vivo labelled enzyme has shown phosphorylation of Ser-15 in SS2. The present work provides evidence that maize sucrose synthase is the physiological substrate of the endogenous calcium and phospholipid dependent protein kinase(s).