CD46

CD46

Pathway Diagram

```mermaid
flowchart TD
CD4["CD4<br/>T-helper cell receptor"]

CD4 -->|"regulates"| Neurodegeneration["Neurodegeneration<br/>Process"]
CD4 -->|"activates"| MS["Multiple Sclerosis<br/>Autoimmune demyelination"]
CD4 -->|"inhibits"| ALS["Amyotrophic Lateral Sclerosis<br/>Motor neuron disease"]
CD4 -->|"regulates"| PD["Parkinson's Disease<br/>Dopaminergic degeneration"]
CD4 -->|"regulates"| Dementia["Dementia<br/>Cognitive decline"]

CD4 -->|"regulates"| Inflammation["Neuroinflammation<br/>Immune activation"]
CD4 -->|"regulates"| Autoimmune["Autoimmune Response<br/>Self-reactive immunity"]

Inflammation -->|"promotes"| Neurodegeneration
Inflammation -->|"contributes_to"| MS
Inflammation -->|"damages"| PD

Autoimmune -->|"drives"| MS
Autoimmune -->|"influences"| Neurodegeneration

CD4 -->|"activates"| Aging["Cellular Aging<br/>Senescence processes"]
Aging -->|"accelerates"| Neurodegeneration
Aging -->|"increases_risk"| Dementia

CD4 -->|"therapeutic_target"| MS_Treatment["MS Therapeutics<br/>Immunomodulation"]
CD4 -->|"therapeutic_target"| Neuro_Treatment["Neurodegeneration<br/>Therapeutics"]
CD4 -->|"biomarker_for"| ALS_Diagnosis["ALS Biomarker<br/>Disease monitoring"]

style CD4 fill:#006494
style MS_Treatment fill:#1b5e20
style Neuro_Treatment fill:#1b5e20
style ALS_Diagnosis fill:#1b5e20
style MS fill:#ef5350
style ALS fill:#ef5350
style Neurodegeneration fill:#ef5350
style Inflammation fill:#ef5350
style Auto

CD46

Pathway Diagram

Introduction

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.

<div class="infobox infobox-gene"> [@liszewski2005]
<div class="infobox-header">CD46 Molecule</div> [@kemper2003]
<div class="infobox-row"><span class="infobox-label">Gene Symbol</span><span class="infobox-value">CD46</span></div> [@astier2006]
<div class="infobox-row"><span class="infobox-label">Full Name</span><span class="infobox-value">CD46 Molecule (Membrane Cofactor Protein)</span></div> [@cardone2010]
<div class="infobox-row"><span class="infobox-label">Chromosomal Location</span><span class="infobox-value">1q32.2</span></div> [@fischer2006]
<div class="infobox-row"><span class="infobox-label">NCBI Gene ID</span><span class="infobox-value">[4179](https://www.ncbi.nlm.nih.gov/gene/4179)</span></div> [@wang2012]
<div class="infobox-row"><span class="infobox-label">OMIM</span><span class="infobox-value">[120745](https://omim.org/entry/120745)</span></div> [@crawford2003]
<div class="infobox-row"><span class="infobox-label">Ensembl ID</span><span class="infobox-value">ENSG00000108539</span></div>
<div class="infobox-row"><span class="infobox-label">UniProt ID</span><span class="infobox-value">[P15529](https://www.uniprot.org/uniprot/P15529)</span></div>
<div class="infobox-row"><span class="infobox-label">Associated Diseases</span><span class="infobox-value">Age-Related Macular Degeneration, Multiple Sclerosis</span></div>
</div>

Overview

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].

Function

The CD46 protein functions as:

Disease Associations

Age-Related Macular Degeneration

• CD46 variants are associated with AMD risk
• CD46 plays a role in retinal pigment epithelial cell protection
• Altered complement regulation contributes to drusen formation

Multiple Sclerosis

• CD46 is implicated in MS pathogenesis
• Regulates immune cell function and neuroinflammation
• May influence disease progression and severity

Other Conditions

• 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

Expression

Tissue Distribution

• Ubiquitous: Expressed on most nucleated cells
• Brain: [Neurons](/entities/neurons), [astrocytes](/entities/astrocytes), [microglia](/cell-types/microglia-neuroinflammation) express CD46
• Immune cells: High expression on leukocytes
• Epithelial cells: Strong expression on mucosal surfaces

Regulation

• Cytokines can modulate CD46 expression
• IFN-α and IFN-β upregulate CD46
• Cell activation increases CD46 surface expression

Genetics

• Located at 1q32.2 in the RCA gene cluster
• Multiple isoforms generated by alternative splicing
• Polymorphisms affect disease susceptibility

Clinical Significance

• 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

Background

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.

External Links

• [NCBI Gene: CD46](https://www.ncbi.nlm.nih.gov/gene/4179)
• [UniProt: CD46](https://www.uniprot.org/uniprot/P15529)
• [OMIM: CD46](https://omim.org/entry/120745)
• [Ensembl: CD46](https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000108539)
• [GeneCards: CD46](https://www.genecards.org/cgi-bin/carddisp.pl?gene=CD46)

References