title: AtPAP2 modulates the import of the small subunit of Rubisco into chloroplasts.
abstract: Arabidopsis thaliana purple acid phosphatase 2 (AtPAP2) is the only phosphatase that is dual-targeted to both chloroplasts and mitochondria. Like Toc33/34 of the TOC and Tom 20 of the TOM, AtPAP2 is anchored to the outer membranes of chloroplasts and mitochondria via a hydrophobic C-terminal motif. AtPAP2 on the mitochondria was previously shown to recognize the presequences of several nuclear-encoded mitochondrial proteins and modulate the import of pMORF3 into the mitochondria. Here we show that AtPAP2 binds to the small subunit of Rubisco (pSSU) and that chloroplast import experiments demonstrated that pSSU was imported less efficiently into pap2 chloroplasts than into wild-type chloroplasts. We propose that AtPAP2 is an outer membrane-bound phosphatase receptor that facilitates the import of selected proteins into chloroplasts.
authors.affiliation: a School of Biological Sciences, The University of Hong Kong , Pokfulam, Hong Kong , China.
authors.forename: Renshan
authors.initials: R
authors.lastname: Zhang
authors.affiliation: a School of Biological Sciences, The University of Hong Kong , Pokfulam, Hong Kong , China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Guan
authors.affiliation: a School of Biological Sciences, The University of Hong Kong , Pokfulam, Hong Kong , China.
authors.forename: Yee-Song
authors.initials: YS
authors.lastname: Law
authors.affiliation: a School of Biological Sciences, The University of Hong Kong , Pokfulam, Hong Kong , China.
authors.forename: Feng
authors.initials: F
authors.lastname: Sun
authors.affiliation: b Centre for Protein Science and Crystallography, School of Life Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong , China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.affiliation: b Centre for Protein Science and Crystallography, School of Life Sciences, The Chinese University of Hong Kong , Shatin, Hong Kong , China.
authors.forename: Kam Bo
authors.initials: KB
authors.lastname: Wong
authors.affiliation: a School of Biological Sciences, The University of Hong Kong , Pokfulam, Hong Kong , China.|c State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong , Shatin, Hong Kong , China.
authors.forename: Boon Leong
authors.initials: BL
authors.lastname: Lim
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D002736:Chloroplasts / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D021122:Protein Subunits; D012273:Ribulose-Bisphosphate Carboxylase
keywords: AtPAP2; Rubisco; chloroplast; outer membrane; protein import; purple acid phosphatase; transit peptide