title: The lipophilicity of phorbol esters as a critical factor in determining the pattern of translocation of protein kinase C delta fused to green fluorescent protein.
abstract: Our previous study showed differential subcellular localization of protein kinase C (PKC) delta by phorbol esters and related ligands, using a green fluorescent protein-tagged construct in living cells. Here we compared the abilities of a series of symmetrically substituted phorbol 12,13-diesters to translocate PKC delta. In vitro, the derivatives bound to PKC with similar potencies but differed in rate of equilibration. In vivo, the phorbol diesters with short, intermediate, and long chain fatty acids induced distinct patterns of translocation. Phorbol 12,13-dioctanoate and phorbol 12,13-nonanoate, the intermediate derivatives and most potent tumor promoters, showed patterns of translocation typical of phorbol 12-myristate 13-acetate, with plasma membrane and subsequent nuclear membrane translocation. The more hydrophilic compounds (phorbol 12,13-dibutyrate and phorbol 12,13-dihexanoate) induced a patchy distribution in the cytoplasm, more prominent nuclear membrane translocation, and little plasma membrane localization at all concentrations examined (100 nM to 10 microM). The highly lipophilic derivatives, phorbol 12,13-didecanoate and phorbol 12, 13-diundecanoate, at 1 microM caused either plasma membrane translocation only or no translocation at incubation times up to 60 min. Our results indicate that lipophilicity of phorbol esters is a critical factor contributing to differential PKC delta localization and thereby potentially to their different biological activities.
authors.affiliation: Molecular Mechanisms of Tumor Promotion Section, Laboratory of Cellular Carcinogenesis and Tumor Promotion, NCI, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Q J
authors.initials: QJ
authors.lastname: Wang
authors.forename: T W
authors.initials: TW
authors.lastname: Fang
authors.forename: D
authors.initials: D
authors.lastname: Fenick
authors.forename: S
authors.initials: S
authors.lastname: Garfield
authors.forename: B
authors.initials: B
authors.lastname: Bienfait
authors.forename: V E
authors.initials: VE
authors.lastname: Marquez
authors.forename: P M
authors.initials: PM
authors.lastname: Blumberg
mesh_terms: D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D006224:Cricetinae; D049452:Green Fluorescent Proteins; D007527:Isoenzymes / Q000235:genetics*; D050356:Lipid Metabolism; D008164:Luminescent Proteins / Q000235:genetics; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D010703:Phorbol Esters / Q000378:metabolism*; D011493:Protein Kinase C / Q000235:genetics*; D051745:Protein Kinase C-delta; D011993:Recombinant Fusion Proteins / Q000235:genetics* / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D007527:Isoenzymes; D008164:Luminescent Proteins; D010703:Phorbol Esters; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D013755:Tetradecanoylphorbol Acetate