Proteomic analysis reveals a role for protein kinase C-alpha in phagosome maturation.

TitleProteomic analysis reveals a role for protein kinase C-alpha in phagosome maturation.
Publication TypeJournal Article
Year of Publication2004
AuthorsHing, JDerek Ng Y, Desjardins, M, Descoteaux, A
JournalBiochem Biophys Res Commun
Date Published2004 Jul 02
KeywordsAnimals, Antigens, CD, Biomarkers, Cathepsin D, Cathepsins, Cell Line, Lysosome-Associated Membrane Glycoproteins, Lysosomes, Macrophages, Membrane Proteins, Mice, Microspheres, Mutation, Phagosomes, Protein Kinase C, Protein Kinase C-alpha, Proteome, rab GTP-Binding Proteins

Acquisition of microbicidal properties by phagosomes requires the action of molecules which regulate the interactions between phagosomes and endocytic organelles. Members of the protein kinase C (PKC) superfamily of serine/threonine kinases are recruited to phagosomes with various kinetics during phagolysosome biogenesis. To study the role of PKC-alpha in this process, we compared the composition of latex bead-containing phagosomes isolated from control and dominant-negative (DN) PKC-alpha-overexpressing RAW 264.7 macrophages. Western blot analysis indicated that the levels of both lysosomal-associated membrane protein-1 and flotillin-1, which are acquired through interactions with late endosomes and lysosomes, are reduced in phagosomes from DN PKC-alpha-overexpressing macrophages. Proteomic characterization of latex bead-containing phagosomes revealed that recruitment of the small GTPase Rab7, cathepsin D, and cathepsin S is inhibited by DN PKC-alpha. Collectively, these data provide evidence that PKC-alpha plays a role in phagolysosome biogenesis, a critical process of the innate immune response against infections.

Alternate JournalBiochem Biophys Res Commun
PubMed ID15184055