ABCB8: ATP Binding Cassette Subfamily B Member 8
Mitochondrial ABC Transporter Involved in Iron Homeostasis and Cardiomyopathy
Gene Information Card
| Symbol | ABCB8 |
|---|---|
| Full Name | ATP binding cassette subfamily B member 8 |
| Gene Type | Protein coding |
| Chromosomal Location | 7q36.1 |
| NCBI Gene ID | 11194 ncbi.nlm.nih.gov/gene/11194 |
| Ensembl ID | ENSG00000105971 |
| UniProt ID | Q9NUT2 |
| OMIM ID | 605464 |
| HGNC ID | HGNC:48 |
| Aliases | M-ABC1, MABC1, MITOSUR |
Description
ABCB8 (ATP binding cassette subfamily B member 8) encodes a mitochondrial ATP-binding cassette (ABC) transporter localized to the inner mitochondrial membrane. It functions in iron homeostasis by exporting mitochondrial iron to the cytosol, and is also involved in mitochondrial potassium transport and protection against oxidative stress. Mutations in ABCB8 are associated with dilated cardiomyopathy and other cardiac disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Dilated cardiomyopathy (DCM) | Loss-of-function mutations impair mitochondrial iron export, leading to iron accumulation, oxidative stress, and cardiac dysfunction. | ClinVar, OMIM |
| Cardiomyopathy, dilated, 1NN (CMD1NN) | Homozygous or compound heterozygous mutations in ABCB8 cause early-onset dilated cardiomyopathy with variable penetrance. | OMIM #615373 |
| Iron overload disorders | Defective ABCB8 disrupts mitochondrial iron efflux, contributing to cellular iron dyshomeostasis. | UniProt, NCBI Gene Reviews |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 12.5 | Medium |
| Skeletal muscle | 8.3 | Medium |
| Liver | 6.1 | Low |
| Kidney | 5.4 | Low |
| Brain | 4.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Cardiomyocytes (AC16) | 14.8 | High expression; relevant to cardiac function |
| HepG2 | 7.2 | Moderate expression |
| HEK293 | 5.9 | Low expression |
| K562 | 3.1 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.574C>T (p.Arg192Trp) | Missense | Rare | Loss of function; associated with dilated cardiomyopathy |
| c.1003G>A (p.Gly335Arg) | Missense | Rare | Impaired mitochondrial iron export; pathogenic in DCM |
| c.1282C>T (p.Arg428Cys) | Missense | Rare | Reduced protein stability; reported in ClinVar as likely pathogenic |
Mutation functional classification
Loss of Function (LOF)
Missense mutations (e.g., p.Arg192Trp, p.Gly335Arg) reduce or abolish mitochondrial iron export activity, leading to iron accumulation and oxidative stress.
Gain of Function (GOF)
No gain-of-function mutations have been reported for ABCB8.
Dominant Negative (DN)
No dominant-negative mutations have been described for ABCB8.
View complete mutation data：
Gene Ontology (GO)
| • GO:0005524 - ATP binding | • GO:0016887 - ATP hydrolysis activity |
| • GO:0005743 - mitochondrial inner membrane | • GO:0006826 - iron ion transport |
| • GO:0015232 - heme transporter activity | • GO:0035435 - phosphate ion transmembrane transport |
| • GO:0098655 - cation transmembrane transport |
Pathways
• Mitochondrial iron-sulfur cluster biogenesis
• Heme biosynthesis
• ABC transporter-mediated mitochondrial iron export
Protein Summary
ABCB8 is a 718-amino acid mitochondrial inner membrane ABC transporter (UniProt Q9NUT2). It forms a homodimer and uses ATP hydrolysis to export iron from the mitochondrial matrix to the cytosol, a critical step for cellular iron homeostasis. The protein also mediates potassium influx into mitochondria, influencing mitochondrial membrane potential and protecting against apoptosis. Structural studies indicate a typical ABC transporter architecture with two transmembrane domains and two nucleotide-binding domains.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ABCB8 Knockout HEK293 Cell Line | EDJ-KQ7326 | Human | 11194 | Details Get a Quote |
| ABCB8 Knockout A-549 Cell Line | EDJ-KQ32404 | Human | 11194 | Details Get a Quote |
| ABCB8 Knockout HCT 116 Cell Line | EDJ-KQ32405 | Human | 11194 | Details Get a Quote |
| ABCB8 Knockout HeLa Cell Line | EDJ-KQ32406 | Human | 11194 | Details Get a Quote |
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