Cd46 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
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Gene SymbolCD46
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Full NameCD46 Molecule (Membrane Cofactor Protein)
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Chromosomal Location1q32.2
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NCBI Gene ID[4179](https://www.ncbi.nlm.nih.gov/gene/4179)
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OMIM[120745](https://omim.org/entry/120745)
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Ensembl IDENSG00000108539
UniProt ID[P15529](https://www.uniprot.org/uniprot/P15529)
Associated DiseasesAge-Related Macular Degeneration, Multiple Sclerosis
The CD46 gene encodes membrane cofactor protein (MCP), a crucial complement regulatory protein expressed on all nucleated cells. CD46 is a type I membrane protein that serves as a cofactor for factor I-mediated cleavage of C3b and C4b, protecting cells from complement-mediated damage [1].
CD46 is a member of the regulators of complement activation (RCA) gene family. The protein exists in multiple isoforms generated by alternative splicing, with different cytoplasmic tails that can signal differently. CD46 also serves as a receptor for several pathogens, including measles virus, adenovirus, and Streptococcus pyogenes [2].
The CD46 protein functions as:
- Complement Regulation: Serves as a cofactor for factor I cleavage of C3b and C4b, preventing complement activation on host cells
- Host Cell Protection: Protects cells from complement-mediated lysis by regulating C3b deposition
- Pathogen Receptor: Serves as a receptor for measles virus, adenovirus types 2 and 5, and Streptococcus pyogenes
- Immune Modulation: Modulates T cell function and promotes regulatory T cell development
- Signal Transduction: Can trigger intracellular signaling upon ligand binding
- CD46 variants are associated with AMD risk
- CD46 plays a role in retinal pigment epithelial cell protection
- Altered complement regulation contributes to drusen formation
- CD46 is implicated in MS pathogenesis
- Regulates immune cell function and neuroinflammation
- May influence disease progression and severity
- Atypical Hemolytic Uremic Syndrome: CD46 mutations can contribute to aHUS
- Chronic Lymphocytic Leukemia: CD46 overexpression may promote immune evasion
- Asthma: CD46 variants associated with disease severity
- Ubiquitous: Expressed on most nucleated cells
- Brain: Neurons, astrocytes, microglia express CD46
- Immune cells: High expression on leukocytes
- Epithelial cells: Strong expression on mucosal surfaces
- Cytokines can modulate CD46 expression
- IFN-α and IFN-β upregulate CD46
- Cell activation increases CD46 surface expression
- Located at 1q32.2 in the RCA gene cluster
- Multiple isoforms generated by alternative splicing
- Polymorphisms affect disease susceptibility
- Therapeutic Target: CD46-targeted therapies in development for cancer and infections
- Biomarker: CD46 expression levels may have diagnostic utility
- Vaccine Vector: CD46 used as receptor for viral vaccine vectors
The study of Cd46 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.