PKC-epsilon regulates basolateral endocytosis in human T84 intestinal epithelia: role of F-actin and MARCKS.
Protein kinase C (PKC) and the actin cytoskeleton are critical effectors of membrane trafficking in mammalian cells. In polarized epithelia, the role of these factors in endocytic events at either the apical or basolateral membrane is poorly defined. In the present study, phorbol 12-myristate 13-acetate (PMA) and other activators of PKC selectively enhanced basolateral but not apical fluid-phase endocytosis in human T84 intestinal epithelia. Stimulation of basolateral endocytosis was blocked by the conventional and novel PKC inhibitor Gö-6850, but not the conventional PKC inhibitor Gö-6976, and correlated with translocation of the novel PKC isoform PKC-epsilon. PMA treatment induced remodeling of basolateral F-actin. The actin disassembler cytochalasin D stimulated basolateral endocytosis and enhanced stimulation of endocytosis by PMA, whereas PMA-stimulated endocytosis was blocked by the F-actin stabilizers phalloidin and jasplakinolide. PMA induced membrane-to-cytosol redistribution of the F-actin cross-linking protein myristoylated alanine-rich C kinase substrate (MARCKS). Cytochalasin D also induced MARCKS translocation and enhanced PMA-stimulated translocation of MARCKS. A myristoylated peptide corresponding to the phosphorylation site domain of MARCKS inhibited both MARCKS translocation and PMA stimulation of endocytosis. MARCKS translocation was inhibited by Gö-6850 but not Gö-6976. The results suggest that a novel PKC isoform, likely PKC-epsilon, stimulates basolateral endocytosis in model epithelia by a mechanism that involves F-actin and MARCKS.
Song
J C
JC
Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
Hrnjez
B J
BJ
Farokhzad
O C
OC
Matthews
J B
JB
D000098:Acetophenones / Q000494:pharmacology; D000109:Acetylcholine / Q000031:analogs & derivatives; D008841:Actin Cytoskeleton / Q000378:metabolism; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D001578:Benzopyrans / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D002217:Carbachol / Q000494:pharmacology; D002227:Carbazoles / Q000494:pharmacology; D002273:Carcinogens / Q000494:pharmacology; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology; D002478:Cells, Cultured; D018679:Cholinergic Agonists / Q000494:pharmacology; D003432:Cross-Linking Reagents / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D004075:Diglycerides / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000737:chemistry / Q000166:cytology / Q000201:enzymology*; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007422:Intestines / Q000166:cytology; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008301:Maleimides / Q000494:pharmacology; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010873:Pinocytosis / Q000187:drug effects / Q000502:physiology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051744:Protein Kinase C-epsilon; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D000098:Acetophenones; D000199:Actins; D001578:Benzopyrans; D002227:Carbazoles; D002273:Carcinogens; D018679:Cholinergic Agonists; D003432:Cross-Linking Reagents; D004075:Diglycerides; D004791:Enzyme Inhibitors; D007211:Indoles; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; C000619710:MARCKS protein, human; D008301:Maleimides; D008565:Membrane Proteins; D019384:Nucleic Acid Synthesis Inhibitors; D011506:Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; C081021:Go 6976; D015638:Cytochalasin D; D002217:Carbachol; C085746:rottlerin; C497255:PRKCE protein, human; D011493:Protein Kinase C; D051744:Protein Kinase C-epsilon; C070515:bisindolylmaleimide I; D000109:Acetylcholine; D013755:Tetradecanoylphorbol Acetate