MPEG1 (Macrophage Expressed 1)
A pore-forming protein involved in innate immunity and host defense against intracellular bacteria.
Gene Information Card
| Symbol | MPEG1 |
|---|---|
| Full Name | Macrophage Expressed 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 11q12.1 |
| NCBI Gene ID | 219972 ncbi.nlm.nih.gov/gene/219972 |
| Ensembl ID | ENSG00000187672 |
| UniProt ID | Q2M3G0 |
| OMIM ID | 616993 |
| HGNC ID | 25926 |
| Aliases | Perforin-2, Mpeg1, P2 |
Description
MPEG1 (Macrophage Expressed 1) encodes perforin-2, a pore-forming protein that is constitutively expressed in macrophages and other phagocytes. Perforin-2 is essential for the elimination of intracellular bacteria by disrupting bacterial membranes within phagolysosomes. It plays a critical role in innate immunity and host defense against a broad range of Gram-negative and Gram-positive pathogens.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Primary immunodeficiency with susceptibility to mycobacterial infection | Loss-of-function mutations in MPEG1 impair bacterial killing, leading to recurrent mycobacterial infections. | OMIM #616993; ClinVar |
| Recurrent bacterial infections (e.g., Salmonella, Listeria) | Defective perforin-2 activity compromises clearance of intracellular bacteria. | Case reports; PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Spleen | 23.4 | High |
| Lung | 18.7 | High |
| Bone marrow | 15.2 | High |
| Blood (whole) | 12.1 | Medium |
| Liver | 8.5 | Medium |
| Small intestine | 6.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| THP-1 (monocyte) | 45.2 | High expression; inducible by LPS |
| U937 (macrophage) | 38.9 | High expression; differentiation-dependent |
| HL-60 (promyeloblast) | 12.4 | Moderate expression |
| HeLa (cervical) | 1.2 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon; predicted loss of function |
| c.202C>T (p.Arg68*) | Nonsense | Rare | Premature stop; loss of function |
| c.497G>A (p.Arg166Gln) | Missense | Rare | Impaired pore formation; reduced bactericidal activity |
Mutation functional classification
Loss of Function (LOF)
Nonsense and missense mutations that disrupt the pore-forming domain or abolish protein expression lead to loss of bactericidal activity.
Gain of Function (GOF)
No gain-of-function mutations have been reported for MPEG1.
Dominant Negative (DN)
No dominant-negative mutations have been described; MPEG1 is thought to function as an oligomer, but dominant effects are not established.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Innate immune system (Reactome: R-HSA-168249)
• Antimicrobial peptides (Reactome: R-HSA-6803157)
Protein Summary
Perforin-2 (MPEG1) is a 718-amino acid pore-forming protein with a MACPF (membrane attack complex/perforin) domain. It is synthesized as a precursor and cleaved to generate an active form that oligomerizes and inserts into bacterial membranes, forming pores that disrupt the pathogen. The protein is predominantly expressed in macrophages, monocytes, and neutrophils, and its expression is upregulated by interferon-gamma and bacterial stimuli. Perforin-2 is critical for the clearance of intracellular bacteria such as Mycobacterium tuberculosis, Salmonella enterica, and Listeria monocytogenes.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| MPEG1 Knockout HEK293 Cell Line | EDJ-KQ8466 | Human | 219972 | Details Get a Quote |
| MPEG1 Knockout HeLa Cell Line | EDJ-KQ59122 | Human | 219972 | Details Get a Quote |
| MPEG1 Knockout A-549 Cell Line | EDJ-KQ67596 | Human | 219972 | Details Get a Quote |
| MPEG1 Knockout HCT 116 Cell Line | EDJ-KQ75987 | Human | 219972 | Details Get a Quote |
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