Protein kinase C-delta C2-like domain is a binding site for actin and enables actin redistribution in neutrophils.
Neutrophils play a key role in host-defence mechanisms against invading pathogens, using their capacity to migrate, engulf micro-organisms and produce toxic radicals. Protein kinase C (PKC) isotypes are important intracellular regulators of these processes in neutrophils. PKC isotypes themselves are controlled by interactions with lipids, Ca(2+) and proteins. The C2-like domain of PKC-delta (deltaC2) has been identified as a protein-interaction domain in this PKC isotype. In the present paper we have investigated the contribution of protein interactions at this domain to the regulation/function of PKC-delta in neutrophils. Using affinity chromatography we identified actin as a deltaC2 binding partner in these cells. Fluorescein-labelled deltaC2, microinjected into immobilized neutrophils, interacts with filamentous actin (F-actin) inside the cell. PKC-delta co-localizes with F-actin in neutrophils, in lamellipodia at the leading edge of the cell. Stimulation with phorbol ester or IgG-opsonized Staphylococcus aureus results in co-ordinated redistribution of PKC-delta and F-actin, and a PKC-delta inhibitor inhibits these changes. Microinjection of deltaC2 also inhibits F-actin redistribution. Thus PKC-delta binds to F-actin through its C2 domain, and these interactions are important in regulating actin redistribution in neutrophils.
López-Lluch
G
G
Centre for Molecular Medicine, Department of Medicine, University College London, The Rayne Institute, 5 University Street, London WC1E 6JJ, UK.
Bird
M M
MM
Canas
B
B
Godovac-Zimmerman
J
J
Ridley
A
A
Segal
A W
AW
Dekker
L V
LV
D000199:Actins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D001665:Binding Sites; D002846:Chromatography, Affinity; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000097:blood* / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D008845:Microinjections; D008969:Molecular Sequence Data; D018482:Muscle, Skeletal / Q000378:metabolism; D009504:Neutrophils / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry; D011493:Protein Kinase C / Q000097:blood* / Q000737:chemistry* / Q000302:isolation & purification; D051745:Protein Kinase C-delta; D021381:Protein Transport; D011554:Pseudopodia / Q000378:metabolism / Q000648:ultrastructure; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014357:Trypsin
D000199:Actins; D007527:Isoenzymes; D010446:Peptide Fragments; C497258:PRKCD protein, human; D011493:Protein Kinase C; D051745:Protein Kinase C-delta; D014357:Trypsin