title: Protein phosphatase 2A regulatory subunits are starting to reveal their functions in plant metabolism and development.
abstract: Canonical protein phosphatase 2A (PP2A) consists of a catalytic subunit (C), a scaffolding subunit (A), and a regulatory subunit (B). The B subunits are believed to confer substrate specificity and cellular localization to the PP2A complex, and are generally divided into three non-related families in plants, i.e., B55, B' and B''. The two Arabidopsis B55 subunits (α and β) interact with nitrate reductase (NR) in the bimolecular fluorescence complementation assay in planta, and are necessary for rapid activation of NR. Interestingly, knockout of all four B55 alleles is probably lethal, because a homozygous double knockout (pp2a-b55αβ) could not be found. The B55 subunits, therefore, appear to have essential functions that cannot be replaced by other regulatory B subunits. A double mutant (pp2a-b'αβ) of two close B' homologs show severely impaired fertility, pointing to the essential role also of B' subunits in plant development.
authors.affiliation: University of Stavanger, Centre for Organelle Research, Faculty of Science and Technology, Stavanger, Norway.
authors.forename: Else Müller
authors.initials: EM
authors.lastname: Jonassen
authors.forename: Behzad
authors.initials: B
authors.lastname: Heidari
authors.forename: Dugassa
authors.initials: D
authors.lastname: Nemie-Feyissa
authors.forename: Polina
authors.initials: P
authors.lastname: Matre
authors.forename: Cathrine
authors.initials: C
authors.lastname: Lillo
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D055786:Gene Knockout Techniques; D009154:Mutation; D050901:Nitrate Reductase / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism*
chemical_list: D021122:Protein Subunits; D050901:Nitrate Reductase; D054648:Protein Phosphatase 2