title: Regulation of self-glycosylation of reversibly glycosylated polypeptides from Solanum tuberosum.
abstract: Reversibly glycosylated polypeptides (RGPs) belong to a family of self-glycosylating proteins believed to be involved in plant polysaccharide synthesis. The precise function of these enzymes remains to be elucidated. Our results showed that the RGP 38-kDa subunit is phosphorylated in potato extracts (Solanum tuberosum L.). An increase in the self-glycosylation of Solanum tuberosum RGP (StRGP) 38-kDa subunit was observed after alkaline phosphatase (AP) treatment. Our results suggest that phosphorylation of StRGP appears to regulate its self-glycosylation. It was determined that when the StRGP reaction was carried out in the presence of UDP-[(14)C]Glc as the sugar donor and then 1 mM UDP was added in a chase-out experiment, radioactive UDP-Glc was obtained indicating that StRGP reaction seems to be reversible. The anomeric configuration of transferred sugars to StRGP protein was also studied.
authors.affiliation: Plant Biochemistry Laboratory, Instituto de Investigaciones Bioquímicas Fundación Instituto Leloir formerly Fundación Campomar, Avenue. Patricias Argentinas 435 (1405) Buenos Aires, Argentina.
authors.forename: Pamela
authors.initials: P
authors.lastname: Testasecca
authors.forename: Flavia A.
authors.initials: FA
authors.lastname: Wald
authors.forename: María E.
authors.initials: ME
authors.lastname: Cozzarín
authors.forename: Silvia
authors.initials: S
authors.lastname: Moreno