HADHB Gene (Hydroxyacyl-CoA Dehydrogenase Trifunctional Multienzyme Complex Subunit Beta)
Mitochondrial trifunctional protein subunit beta; key enzyme in fatty acid beta-oxidation
Gene Information Card
| Symbol | HADHB |
|---|---|
| Full Name | Hydroxyacyl-CoA Dehydrogenase Trifunctional Multienzyme Complex Subunit Beta |
| Gene Type | Protein coding |
| Chromosomal Location | 2p23.3 |
| NCBI Gene ID | 3032 ncbi.nlm.nih.gov/gene/3032 |
| Ensembl ID | ENSG00000138029 |
| UniProt ID | P55084 |
| OMIM ID | 143450 |
| HGNC ID | 4803 |
| Aliases | MTPB, MSTP029, TP-beta |
Description
The HADHB gene encodes the beta subunit of the mitochondrial trifunctional protein (MTP), which catalyzes the last three steps of long-chain fatty acid beta-oxidation. The beta subunit possesses 3-ketoacyl-CoA thiolase activity. Mutations in HADHB cause mitochondrial trifunctional protein deficiency, leading to impaired fatty acid oxidation and multisystem disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Mitochondrial trifunctional protein deficiency (MTPD) | Loss-of-function mutations in HADHB impair beta-oxidation of long-chain fatty acids, causing energy deficiency and accumulation of toxic metabolites. | ClinVar, OMIM #609015 |
| Long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD) deficiency | While primarily associated with HADHA, HADHB mutations can also present with similar biochemical phenotype due to MTP complex instability. | OMIM #609016 |
| Acute fatty liver of pregnancy (AFLP) | Maternal heterozygosity for HADHB mutations may predispose to AFLP when fetus is affected. | OMIM #143450 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | High |
| Heart | 10.2 | High |
| Skeletal Muscle | 8.9 | High |
| Kidney | 6.1 | Medium |
| Brain | 3.4 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 14.1 | Hepatocyte cell line |
| K-562 | 7.8 | Myelogenous leukemia |
| HeLa | 5.2 | Cervical carcinoma |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.739C>T (p.Arg247*) | Nonsense | Rare | Loss of function; truncation of beta subunit |
| c.1331G>A (p.Arg444Gln) | Missense | Rare | Impaired thiolase activity |
| c.209+1G>A | Splice site | Rare | Exon skipping; loss of function |
Mutation functional classification
Loss of Function (LOF)
Most HADHB mutations are loss-of-function, reducing or abolishing thiolase activity and MTP complex stability.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
Some missense mutations may exert dominant-negative effects by disrupting MTP complex assembly.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Fatty acid beta-oxidation (mitochondrial)
• Metabolism of lipids and lipoproteins
Protein Summary
The HADHB protein (55084) is the beta subunit of the mitochondrial trifunctional protein (MTP). It catalyzes the thiolysis of 3-ketoacyl-CoA to acyl-CoA and acetyl-CoA, the final step of mitochondrial beta-oxidation. The protein forms a hetero-octameric complex with the alpha subunit (HADHA). Defects cause metabolic disorders.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| HADHB Knockout HEK293 Cell Line | EDJ-KQ4838 | Human | 3032 | Details Get a Quote |
| HADHB Knockout A-549 Cell Line | EDJ-KQ27617 | Human | 3032 | Details Get a Quote |
| HADHB Knockout HCT 116 Cell Line | EDJ-KQ27618 | Human | 3032 | Details Get a Quote |
| HADHB Knockout HeLa Cell Line | EDJ-KQ27619 | Human | 3032 | Details Get a Quote |
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