title: Dimerization of phospholipase d isozymes.
abstract: Two mammalian phospholipase D (PLD) isozymes (PLD1 and PLD2) have been reported. In this study, we differentially tagged these isozymes with enhanced green fluorescent protein (EGFP-rPLD1 and EGFP-rPLD2) or Xpress peptide epitope (Xpress-rPLD1 and Xpress-rPLD2) to examine the association between these isozymes. Overexpressed EGFP-rPLD1 coimmunoprecipitated with Xpress-rPLD1 using anti-Xpress antibody. However, the coimmunoprecipitation was independent of the activity of rPLD1. Xpress-rPLD2 also bound to EGFP-rPLD1 although the binding was less efficient than observed with Xpress-rPLD1. The association between rPLD2 and rPLD1 was confirmed by coimmunoprecipitation of EGFP-rPLD2 with Xpress-rPLD1. EGFP-rPLD2 also bound to Xpress-rPLD2 as shown by coimmunoprecipitation. Immunofluorescence staining of COS-7 cells coexpressing EGFP-rPLDs and Xpress-rPLDs showed that the PLD isozymes colocalized in the perinuclear and plasma membrane regions, suggesting that they could associate in a cellular setting. These results suggest that rPLD1 and rPLD2 can exist as homodimers and can form heterodimers.
authors.affiliation: Howard Hughes Medical Institute, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
authors.forename: Yoonseok
authors.initials: Y
authors.lastname: Kam
authors.forename: John H
authors.initials: JH
authors.lastname: Exton
mesh_terms: D000818:Animals; D019556:COS Cells; D002478:Cells, Cultured; D019281:Dimerization; D008856:Microscopy, Fluorescence; D010739:Phospholipase D / Q000737:chemistry* / Q000378:metabolism*; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D020033:Protein Isoforms; D014162:Transfection
chemical_list: D020033:Protein Isoforms; D010739:Phospholipase D