MPEG1

The MACPF domain includes the central machinery of pore formation: acidification causes a significant structural rearrangement, leading to oligomerization and deployment of the transmembrane beta-strands (named TMH1 and TMH2) that enter the membrane as amphipathic beta-hairpins.

The P2 region contains beta-hairpins to interact with target membranes.

Pore-forming protein involved in both innate and adaptive immunity. Plays a central role in antigen cross-presentation in dendritic cells by forming a pore in antigen-containing compartments, thereby promoting delivery of antigens for cross-presentation. Also involved in innate immune response following bacterial infection; shows antibacterial activity against a wide spectrum of Gram-positive, Gram-negative and acid-fast bacteria. Reduces the viability of the intracytosolic pathogen L.monocytogenes by inhibiting acidification of the phagocytic vacuole of host cells which restricts bacterial translocation from the vacuole to the cytosol. Required for the antibacterial activity of reactive oxygen species and nitric oxide.

Macrophage-expressed gene 1 protein, processed form

Pore-forming protein that plays a central role in antigen cross-presentation in dendritic cells by mediating delivery of antigens for cross-presentation. Dendritic cells bridge innate and adaptive immunity by capturing exogenous antigens on MHC class-I molecules and presenting them to naive CD8(+) T-cells. Acts by forming a pore in antigen-containing compartments, promoting the release of antigens into the cytosol, enabling generation of MHCI:peptide complexes and T-cell priming.

Proteolytically processed in two steps to generate the Macrophage-expressed gene 1 protein, processed form: cleaved by trypsin in proximity of the helical transmembrane domain releases the ectodomain into the lysosomal lumen to orient the pore-forming domain toward the endogenous membranes, and processed by the asparagine endopeptidase (LGMN). Proteolytic processing in antigen-containing vesicles is pH-dependent.

Monoubiquitinated in response to bacterial infection; ubiquitination is required for vesicular localization and antibacterial activity and can be blocked by bacterial cell cycle inhibiting factor (cif).

Belongs to the MPEG1 family.

• Cytoplasmic vesicle membrane
• Multi-pass membrane protein
• Bacterial infection induces translocation of the cytoplasmic vesicles to bacterium-containing phagocytic vesicles and fusing of the vesicles.
• Macrophage-expressed gene 1 protein, processed form
• Cytoplasmic vesicle
• Phagosome membrane
• Multi-pass membrane protein
• Proteolytically processed in lysosomes, leading to its maturation and forms pores in the membrane of antigen-containing phagosomes.

Macrophage-expressed gene 1 protein, Macrophage gene 1 protein, Mpg-1, Perforin-2, P-2

• swissprot:Q9WV57

Proteins

Immuno-oncology

78527Da