Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/201810
Type: Artigo de periódico
Title: Oligomerization, Membrane Association, And In Vivo Phosphorylation Of Sugarcane Udp-glucose Pyrophosphorylase.
Author: Soares, Jose Sergio M
Gentile, Agustina
Scorsato, Valeria
Lima, Aline da C
Kiyota, Eduardo
Dos Santos, Marcelo Leite
Piattoni, Claudia V
Huber, Steven C
Aparicio, Ricardo
Menossi, Marcelo
Abstract: Sugarcane is a monocot plant that accumulates sucrose to levels of up to 50% of dry weight in the stalk. The mechanisms that are involved in sucrose accumulation in sugarcane are not well understood, and little is known with regard to factors that control the extent of sucrose storage in the stalks. UDP-glucose pyrophosphorylase (UGPase; EC 2.7.7.9) is an enzyme that produces UDP-glucose, a key precursor for sucrose metabolism and cell wall biosynthesis. The objective of this work was to gain insights into the ScUGPase-1 expression pattern and regulatory mechanisms that control protein activity. ScUGPase-1 expression was negatively correlated with the sucrose content in the internodes during development, and only slight differences in the expression patterns were observed between two cultivars that differ in sucrose content. The intracellular localization of ScUGPase-1 indicated partial membrane association of this soluble protein in both the leaves and internodes. Using a phospho-specific antibody, we observed that ScUGPase-1 was phosphorylated in vivo at the Ser-419 site in the soluble and membrane fractions from the leaves but not from the internodes. The purified recombinant enzyme was kinetically characterized in the direction of UDP-glucose formation, and the enzyme activity was affected by redox modification. Preincubation with H2O2 strongly inhibited this activity, which could be reversed by DTT. Small angle x-ray scattering analysis indicated that the dimer interface is located at the C terminus and provided the first structural model of the dimer of sugarcane UGPase in solution.
Subject: Cell Membrane
Gene Expression Regulation, Enzymologic
Gene Expression Regulation, Plant
Models, Molecular
Phosphorylation
Plant Proteins
Plant Stems
Protein Structure, Tertiary
Saccharum
Utp-glucose-1-phosphate Uridylyltransferase
Uridine Diphosphate Glucose
Gene Expression
Kinetics
Protein Phosphorylation
Redox Regulation
Small Angle X-ray Scattering (saxs)
Sucrose
Rights: fechado
Identifier DOI: 10.1074/jbc.M114.590125
Address: http://www.ncbi.nlm.nih.gov/pubmed/25320091
Date Issue: 2014
Appears in Collections:Unicamp - Artigos e Outros Documentos

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