title: Isolation and characterization of a phosphatidylglycerophosphate phosphatase1, PGPP1, in Chlamydomonas reinhardtii.
abstract: Phosphatidylglycerol (PG) is the exclusive phospholipid synthesized in chloroplasts and plays important roles in photosynthesis. However, phosphatidylglycerophosphate phosphatase (PGPP), which catalyzes the final step of PG biosynthesis, is a missing piece in photosynthetic eukaryotes. Here, we isolated a previously uncharacterized haloacid dehalogenase-like phosphatase, designated CrPGPP1, as a putative PGPP in Chlamydomonas reinhardtii. CrPGPP1 complemented growth and lipid compositional defects in Δgep4, a yeast mutant of PGPP, which indicates that CrPGPP1 is a functional PGPP. Two aspartic acid residues, which are both essential for the yeast PGPP (Gep4p) activity, are also conserved in the putative catalytic motif of CrPGPP1. Site-specific mutagenesis showed that the first but not the second aspartic acid residue was required for CrPGPP1 to complement the growth defect of Δgep4 mutant, which highlights the distinct molecular features of CrPGPP1. Our results suggest that CrPGPP1 is a functional PGPP in C. reinhardtii, for the first PGPP in photosynthetic eukaryotes.
authors.affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan.
authors.forename: Chun-Hsien
authors.initials: CH
authors.lastname: Hung
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, Japan; CREST, Japan Science and Technology Agency, Saitama, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Wada
authors.affiliation: Institute of Plant and Microbial Biology, Academia Sinica, Taipei, Taiwan; PRESTO, Japan Science and Technology Agency, Saitama, Japan. Electronic address: nakamura@gate.sinica.edu.tw.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Nakamura
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D001224:Aspartic Acid / Q000378:metabolism; D016825:Chlamydomonas reinhardtii / Q000201:enzymology* / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010715:Phosphatidylglycerols / Q000096:biosynthesis*; D010744:Phosphoric Monoester Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D010788:Photosynthesis; D010940:Plant Proteins / Q000302:isolation & purification* / Q000378:metabolism; D015003:Yeasts / Q000235:genetics / Q000254:growth & development / Q000378:metabolism
chemical_list: D010715:Phosphatidylglycerols; D010940:Plant Proteins; C034358:phosphatidylglycerophosphate; D001224:Aspartic Acid; D010744:Phosphoric Monoester Hydrolases
keywords: Chlamydomonas reinhardtii; Chloroplast; Phosphatidylglycerol; Phosphatidylglycerophosphate phosphatase; Photosynthesis