title: Fused RolA protein enhances beta-glucoronidase activity 50-fold: implication for RolA mechanism of action.
abstract: We report that the plant oncoprotein RolA from Agrobacterium rhizogenes acts to stabilize beta-glucoronidase (Gus) when the two proteins are expressed as a fusion protein in transformed tobacco. The observed 50-fold increase of Gus activity was shown to be related to protein accumulation, with no significant changes in mRNA abundance, kinetic properties of the enzyme and thermostability. The entire RolA sequence is essential to achieve the full effect since both the N-terminal region, spanning a putative reverse signal-anchor and nuclear targeting sequences, or the contiguous C-terminal portion were shown to increase Gus activity only 10-fold. A possible interference of RolA in the protein degradation pathway regulated by auxin is discussed.
authors.affiliation: Embrapa/Genetic Resources and Biotechnology, PqEB, Final W5 Norte, CEP 70.770-900 Brasília, DF, Brazil.
authors.forename: Leila Maria G
authors.initials: LM
authors.lastname: Barros
authors.forename: Rosane H
authors.initials: RH
authors.lastname: Curtis
authors.forename: Antônio Américo B
authors.initials: AA
authors.lastname: Viana
authors.forename: Laura
authors.initials: L
authors.lastname: Campos
authors.forename: Mauro
authors.initials: M
authors.lastname: Carneiro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000378:metabolism*; D015152:Blotting, Northern; D015153:Blotting, Western; D017931:DNA Primers / Q000737:chemistry; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D005966:Glucuronidase / Q000378:metabolism*; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000201:enzymology / Q000378:metabolism; D030821:Plants, Genetically Modified; D010957:Plasmids; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000378:metabolism*; D012231:Rhizobium / Q000737:chemistry; D014026:Nicotiana / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D017931:DNA Primers; D007210:Indoleacetic Acids; D012333:RNA, Messenger; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; C096589:rolA protein, Agrobacterium rhizogenes; D005966:Glucuronidase