GONUTS has been updated to MW1.31 Most things seem to be working but be sure to report problems.

Have any questions? Please email us at ecoliwiki@gmail.com

TableEdit

Jump to: navigation, search

PMID:15788404

You don't have sufficient rights on this wiki to edit tables. Perhaps you need to log in. Changes you make in the Table editor will not be saved back to the wiki

See Help for Help on this wiki. See the documentation for how to use the table editor

Citation

Sakagami, H, Aoki, J, Natori, Y, Nishikawa, K, Kakehi, Y, Natori, Y and Arai, H (2005) Biochemical and molecular characterization of a novel choline-specific glycerophosphodiester phosphodiesterase belonging to the nucleotide pyrophosphatase/phosphodiesterase family. J. Biol. Chem. 280:23084-93

Abstract

Nucleotide pyrophosphatases/phosphodiesterases (NPPs) are ubiquitous membrane-associated or secreted ectoenzymes that release nucleoside 5'-monophosphate from a variety of nucleotides and nucleotide derivatives. The mammalian NPP family comprises seven members, but only three of these (NPP1-3) have been studied in some detail. Previously we showed that lysophospholipase D, which hydrolyzes lysophosphatidylcholine (LPC) to produce lysophosphatidic acid, is identical to NPP2. More recently an uncharacterized novel NPP member (NPP7) was shown to have alkaline sphingomyelinase activity. These findings raised the possibility that other members of the NPP family act on phospholipids. Here we show that the sixth member of the NPP family, NPP6, is a choline-specific glycerophosphodiester phosphodiesterase. The sequence of NPP6 encodes a transmembrane protein containing an NPP domain with significant homology to NPP4, NPP5, and NPP7/alkaline sphingomyelinase. When expressed in HeLa cells, NPP6 was detected in both the cells and the cell culture medium as judged by Western blotting and by enzymatic activity. Recombinant NPP6 efficiently hydrolyzed the classical substrate for phospholipase C, p-nitrophenyl phosphorylcholine, but not the classical nucleotide phosphodiesterase substrate, p-nitrophenyl thymidine 5'-monophosphate. In addition, NPP6 hydrolyzed LPC to form monoacylglycerol and phosphorylcholine but not lysophosphatidic acid, showing it has a lysophospholipase C activity. NPP6 showed a preference for LPC with short (12:0 and 14:0) or polyunsaturated (18:2 and 20:4) fatty acids. It also hydrolyzed glycerophosphorylcholine and sphingosylphosphorylcholine efficiently. In mice, NPP6 mRNA was predominantly detected in kidney with a lesser expression in brain and heart, and in human it was detected in kidney and brain. The present results suggest that NPP6 has a specific role through the hydrolysis of polyunsaturated LPC, glycerophosphorylcholine, or sphingosylphosphorylcholine in these organs.

Links

PubMed Online version:10.1074/jbc.M413438200

Keywords

Amino Acid Sequence; Animals; Antibodies, Monoclonal/chemistry; Base Sequence; Blotting, Northern; Blotting, Western; Brain/enzymology; Cations; Cell Membrane/metabolism; Cell Movement; Fatty Acids/chemistry; Glycerylphosphorylcholine/chemistry; HeLa Cells; Humans; Hydrolysis; Immunohistochemistry; Kidney/enzymology; Kinetics; Lysophosphatidylcholines/chemistry; Lysophosphatidylcholines/metabolism; Mice; Microscopy, Fluorescence; Models, Biological; Models, Chemical; Molecular Sequence Data; Myocardium/enzymology; Nephrons/metabolism; Phospholipids/metabolism; Phosphoric Diester Hydrolases/chemistry; Phosphoric Diester Hydrolases/metabolism; Phosphoric Diester Hydrolases/physiology; Phosphorylcholine/analogs & derivatives; Phosphorylcholine/chemistry; Phylogeny; Protein Binding; Protein Structure, Tertiary; Pyrophosphatases/chemistry; Pyrophosphatases/metabolism; RNA, Messenger/metabolism; Recombinant Proteins/chemistry; Reverse Transcriptase Polymerase Chain Reaction; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Species Specificity; Sphingosine/analogs & derivatives; Sphingosine/chemistry; Swine; Time Factors; Tissue Distribution; Transfection; Type C Phospholipases/chemistry

public



Cancel