title: Endosomal localization of phospholipase D 1a and 1b is defined by the C-termini of the proteins, and is independent of activity.
abstract: The factors regulating the activity of cellular phospholipase D (PLD) have been well characterized; however, the cellular distribution of specific PLD isoforms and the factors defining localization are less clear. Two specific PLD1 isoforms, PLD1a and PLD1b, are shown in the present study to be localized in endosomal compartments with early endosomal autoantigen 1, internalizing epidermal growth factor receptor (ErbB1) and lysobisphosphatidic acid. Novel C-terminal splice variants of PLD1, PLD1a2 and PLD1b2, do not exhibit this endosomal localization. Studies using catalytically inactive and C-terminal deletion mutants of the four PLD1 isoforms led to the conclusion that the C-terminus plays an important part in the catalytic activity of PLD1, but that the endosomal localization of PLD1a and PLD1b is defined by the C-terminus and not catalytic activity.
authors.affiliation: Protein Phosphorylation Laboratory, Imperial Cancer Research Fund, 44, Lincoln's Inn Fields, London WC2A 3PX, UK.
authors.forename: W E
authors.initials: WE
authors.lastname: Hughes
authors.forename: P J
authors.initials: PJ
authors.lastname: Parker
mesh_terms: D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers; D011992:Endosomes / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008969:Molecular Sequence Data; D010739:Phospholipase D / Q000737:chemistry / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D007527:Isoenzymes; D010739:Phospholipase D; C106801:phospholipase D1