Related Experiment Video
Updated: Aug 24, 2026

Identification of Post-translational Modifications of Plant Protein Complexes
Published on: February 22, 2014
Proteomic analysis reveals a role for protein kinase C-alpha in phagosome maturation
John Derek Ng Yan Hing1, Michel Desjardins, Albert Descoteaux
1INRS-Institut Armand-Frappier, Université du Québec, Laval, Que., Canada H7V 1B7.
Abstract:
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.
Related Concept Videos
Bacterial Protein Maturation
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Regulated Protein Degradation
Protein degradation plays two important roles in the cells. It helps to protect cells from misfolded or damaged proteins before they lead to a...
Phosphorylation
During phosphorylation, protein kinases transfer the terminal phosphate group of ATP to specific amino acid side chains of substrate proteins. Serine, threonine, and tyrosine are the most commonly...
The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. This involves participation of a series of enzymes including— E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3 (ubiquitin...
The Proteasome
In this pathway, the target proteins are first tagged with small proteins called ubiquitin. A series of enzymes carry out the ubiquitination of the target proteins - E1 (ubiquitin-activating enzyme), E2 (ubiquitin-conjugating enzyme), and E3...

