Contents

HADHB

Protein-coding gene in the species Homo sapiens

HADHB
Identifiers
Aliases	HADHB, ECHB, MSTP029, MTPB, TP-BETA, hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase/enoyl-CoA hydratase (trifunctional protein), beta subunit, hydroxyacyl-CoA dehydrogenase trifunctional multienzyme complex subunit beta
External IDs	OMIM: 143450; MGI: 2136381; HomoloGene: 153; GeneCards: HADHB; OMA:HADHB - orthologs
Gene location (Human) Chr. Chromosome 2 (human)[1] Band 2p23.3 Start 26,243,170 bp[1] End 26,290,465 bp[1]
Gene location (Mouse) Chr. Chromosome 5 (mouse)[2] Band 5|5 B1 Start 30,360,246 bp[2] End 30,389,591 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in right ventricle myocardium of left ventricle deltoid muscle tibialis anterior muscle jejunal mucosa gastrocnemius muscle Skeletal muscle tissue of rectus abdominis cardiac muscle tissue of right atrium triceps brachii muscle quadriceps femoris muscle Top expressed in spermatocyte muscle of thigh esophagus right kidney spermatid lip genital tubercle yolk sac dentate gyrus of hippocampal formation granule cell tail of embryo More reference expression data BioGPS n/a
Gene ontology Molecular function transferase activity acyltransferase activity, transferring groups other than amino-acyl groups enoyl-CoA hydratase activity long-chain-3-hydroxyacyl-CoA dehydrogenase activity protein binding catalytic activity acyltransferase activity 3-hydroxyacyl-CoA dehydrogenase activity RNA binding acetyl-CoA C-acyltransferase activity long-chain-enoyl-CoA hydratase activity Cellular component membrane mitochondrial outer membrane endoplasmic reticulum mitochondrial inner membrane mitochondrial envelope mitochondrial nucleoid extracellular exosome mitochondrion Biological process lipid metabolism fatty acid metabolic process metabolism cardiolipin acyl-chain remodeling fatty acid beta-oxidation Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 3032 231086 Ensembl ENSG00000138029 ENSMUSG00000059447 UniProt P55084 Q99JY0 RefSeq (mRNA) NM_000183 NM_001281512 NM_001281513 NM_145558 NM_001289798 NM_001289799 RefSeq (protein) NP_000174 NP_001268441 NP_001268442 NP_001276727 NP_001276728 NP_663533 Location (UCSC) Chr 2: 26.24 – 26.29 Mb Chr 5: 30.36 – 30.39 Mb PubMed search [3] [4]
Wikidata
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Trifunctional enzyme subunit beta, mitochondrial (TP-beta) also known as 3-ketoacyl-CoA thiolase, acetyl-CoA acyltransferase, or beta-ketothiolase is an enzyme that in humans is encoded by the HADHB gene.^[5]

HADHB is a subunit of the mitochondrial trifunctional protein and has thiolase activity.

The HADHB gene is located on chromosome 2, with its specific location being 2p23.^[5] The gene contains 17 exons. HADHB encodes a 51.2 kDa protein that is composed of 474 amino acids; 124 peptides have been observed through mass spectrometry data.^[6][7]

This gene encodes the beta subunit of the mitochondrial trifunctional protein, a catalyst of mitochondrial beta-oxidation of long chain fatty acids. The HADHB protein catalyzes the final step of beta-oxidation, in which 3-ketoacyl CoA is cleaved by the thiol group of another molecule of Coenzyme A. The thiol is inserted between C-2 and C-3, which yields an acetyl CoA molecule and an acyl CoA molecule, which is two carbons shorter.

The encoded protein can also bind RNA and decreases the stability of some mRNAs. The genes of the alpha and beta subunits of the mitochondrial trifunctional protein are located adjacent to each other in the human genome in a head-to-head orientation.^[5]

Mutations in this gene, along with mutations in HADHA, result in trifunctional protein deficiency.^[5] Mutations in either gene have similar clinical presentations.^[8] Trifunctional protein deficiency is characterized by decreased activity of long-chain 3-hydroxyacyl-CoA dehydrogenase (LCHAD), long-chain enoyl-CoA hydratase, and long-chain thiolase. This deficiency can be classified into 3 main clinical phenotypes: neonatal onset of a severe, lethal condition resulting in sudden infant death syndrome (SIDS),^[9] infantile onset of a hepatic Reye-like syndrome, and late-adolescent onset of primarily a skeletal myopathy.^[10] Additionally, some presents showed symptoms associated with myopathy, recurrent and episodic rhabdomyolysis, and sensorimotor axonal neuropathy.^[11] In some cases, symptoms of the deficiency can present as dilated cardiomyopathy, congestive heart failure, and respiratory failure. The deficiency has presented as hydrops fetalis and HELLP syndrome in fetuses.^[12] A compound heterozygous mutation of the HADHB gene can cause axonal Charcot-Marie-tooth disease, which is a neurological disorder, which shows that mutations in this gene can result in deficiencies that present in new forms not currently described.^[13]

HADHB is a functional molecular target of ERα in the mitochondria, and the interaction may play an important role in the estrogen-mediated lipid metabolism in animals and humans.^[14] Additionally, HADHB has been shown to bind to the distal 3’ untranslated region of renin mRNA, thereby regulating renin protein expression.^[15]

• Media related to HADHB at Wikimedia Commons
• HADHB+protein,+human at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

This article incorporates text from the United States National Library of Medicine, which is in the public domain.