title: Identification of a mammalian-type phosphatidylglycerophosphate phosphatase in the Eubacterium Rhodopirellula baltica.
abstract: Cardiolipin is a glycerophospholipid found predominantly in the mitochondrial membranes of eukaryotes and in bacterial membranes. Cardiolipin interacts with protein complexes and plays pivotal roles in cellular energy metabolism, membrane dynamics, and stress responses. We recently identified the mitochondrial phosphatase, PTPMT1, as the enzyme that converts phosphatidylglycerolphosphate (PGP) to phosphatidylglycerol, a critical step in the de novo biosynthesis of cardiolipin. Upon examination of PTPMT1 evolutionary distribution, we found a PTPMT1-like phosphatase in the bacterium Rhodopirellula baltica. The purified recombinant enzyme dephosphorylated PGP in vitro. Moreover, its expression restored cardiolipin deficiency and reversed growth impairment in a Saccharomyces cerevisiae mutant lacking the yeast PGP phosphatase, suggesting that it is a bona fide PTPMT1 ortholog. When ectopically expressed, this bacterial PGP phosphatase was localized in the mitochondria of yeast and mammalian cells. Together, our results demonstrate the conservation of function between bacterial and mammalian PTPMT1 orthologs.
authors.affiliation: Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, California 92093, USA.
authors.forename: Phildrich G
authors.initials: PG
authors.lastname: Teh
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Chen
authors.forename: James L
authors.initials: JL
authors.lastname: Engel
authors.forename: Carolyn A
authors.initials: CA
authors.lastname: Worby
authors.forename: Gerard
authors.initials: G
authors.lastname: Manning
authors.forename: Jack E
authors.initials: JE
authors.lastname: Dixon
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000201:enzymology*; D002308:Cardiolipins / Q000737:chemistry; D017124:Conserved Sequence; D004331:Drosophila melanogaster; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D005816:Genetic Complementation Test; D008055:Lipids / Q000737:chemistry; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D008954:Models, Biological; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010715:Phosphatidylglycerols / Q000737:chemistry*; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D002308:Cardiolipins; D008055:Lipids; D010715:Phosphatidylglycerols; C034358:phosphatidylglycerophosphate; D010744:Phosphoric Monoester Hydrolases; C026991:phosphatidylglycerophosphatase