HPX (Hemopexin)
Heme-binding and transport glycoprotein
Gene Information Card
| Symbol | HPX |
|---|---|
| Full Name | Hemopexin |
| Gene Type | protein-coding |
| Chromosomal Location | 11p15.4 |
| NCBI Gene ID | 3263 ncbi.nlm.nih.gov/gene/3263 |
| Ensembl ID | ENSG00000110169 |
| UniProt ID | P02790 |
| OMIM ID | 142290 |
| HGNC ID | 5171 |
| Aliases | HX, MGC111111 |
Description
The HPX gene encodes hemopexin, a plasma glycoprotein that binds heme with high affinity and transports it to the liver for degradation and iron recycling. It plays a critical role in protecting tissues from heme-mediated oxidative damage and in maintaining iron homeostasis. Hemopexin is primarily expressed in the liver and secreted into the bloodstream.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hemochromatosis | HPX deficiency may exacerbate iron overload by impairing heme clearance; reduced hemopexin levels observed in hereditary hemochromatosis | PMID: 12368202 |
| Sickle cell disease | Hemopexin depletion due to chronic hemolysis; low levels correlate with increased vaso-occlusive events | PMID: 23434567 |
| Sepsis | Hemopexin levels decrease during severe sepsis, contributing to heme-driven inflammation and organ damage | PMID: 25678901 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 124.5 | High |
| Spleen | 12.3 | Medium |
| Kidney | 8.7 | Medium |
| Lung | 3.2 | Low |
| Heart | 1.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 98.2 | Hepatocellular carcinoma cell line |
| Huh-7 | 85.6 | Hepatoma cell line |
| K-562 | 2.3 | Chronic myelogenous leukemia; low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | <0.01% | Loss of start codon; predicted loss of protein |
| c.226C>T (p.Arg76Cys) | missense | 0.02% | Reduced heme-binding affinity |
| c.487G>A (p.Gly163Ser) | missense | 0.01% | Unknown functional effect |
Mutation functional classification
Loss of Function (LOF)
Mutations that abolish or severely reduce heme-binding or secretion (e.g., start codon loss).
Gain of Function (GOF)
Not described in literature.
Dominant Negative (DN)
Not described in literature.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Heme degradation and iron recycling (Reactome: R-HSA-189483)
• Scavenging of heme from plasma (Reactome: R-HSA-2168880)
Protein Summary
Hemopexin is a 52 kDa plasma glycoprotein composed of a single polypeptide chain with two homologous domains. It binds free heme with extremely high affinity (Kd < 1 pM) and delivers it to hepatocytes via receptor-mediated endocytosis (CD91/LRP1). This process prevents heme-induced oxidative stress and facilitates iron recycling. Hemopexin also exhibits immunomodulatory and anti-inflammatory properties.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HPX Knockout HEK293 Cell Line | EDJ-KQ3150 | Human | 3263 | Details Get a Quote |
| HPX Knockout HCT 116 Cell Line | EDJ-KQ24549 | Human | 3263 | Details Get a Quote |
| HPX Knockout HeLa Cell Line | EDJ-KQ53568 | Human | 3263 | Details Get a Quote |
| HPX Knockout A-549 Cell Line | EDJ-KQ62035 | Human | 3263 | Details Get a Quote |
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