title: Regulatory phosphorylation of C4 phosphoenolpyruvate carboxylase from Sorghum: An immunological study using specific anti-phosphorylation site-antibodies.
abstract: A peptide containing the N-terminal phosphorylation site (Ser-8) of Sorghum C4-phospho enolpyruvate carboxylase (PEPC) was synthesized, purified and used to raise an antiserum in rabbits. Affinity-purified IgGs prevented PEPC phosphorylation in a reconstituted in vitro assay and reacted with both the phosphorylated and dephosphorylated forms of either native or denatured PEPC in immunoblotting experiments. Saturation of dephospho-PEPC with these specific IgGs resulted in a marked alteration of its functional and regulatory properties that mimicked phosphorylation of Ser-8. A series of recombinant C4 PEPCs mutated in the N-terminal phosphorylation domain and a C3-like PEPC isozyme from Sorghum behaved similarly to their C4 counterpart with respect to these phosphorylation-site antibodies.
authors.affiliation: Institut de Biotechnologie des Plantes, UA CNRS D1128, Université de Paris-Sud, 91405, Orsay Cedex, France.
authors.forename: V
authors.initials: V
authors.lastname: Pacquit
authors.forename: N
authors.initials: N
authors.lastname: Giglioli
authors.forename: C
authors.initials: C
authors.lastname: Crétin
authors.forename: J N
authors.initials: JN
authors.lastname: Pierre
authors.forename: J
authors.initials: J
authors.lastname: Vidal
authors.forename: C
authors.initials: C
authors.lastname: Echevarria