CYB5B
Cytochrome b5 type B (outer mitochondrial membrane) gene
Gene Information Card
| Symbol | CYB5B |
|---|---|
| Full Name | cytochrome b5 type B (outer mitochondrial membrane) |
| Gene Type | protein-coding |
| Chromosomal Location | 16q22.1 |
| NCBI Gene ID | 80777 ncbi.nlm.nih.gov/gene/80777 |
| Ensembl ID | ENSG00000103056 |
| UniProt ID | O43169 |
| OMIM ID | 613946 |
| HGNC ID | 2549 |
| Aliases | OMB5, CYB5-M, MGC117188 |
Description
CYB5B encodes cytochrome b5 type B, a hemoprotein localized to the outer mitochondrial membrane. It functions as an electron carrier in various redox reactions, including fatty acid desaturation and cholesterol biosynthesis. The protein contains a heme-binding domain and is involved in the mitochondrial electron transport chain.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hereditary methemoglobinemia | Deficiency in cytochrome b5 reductase activity; CYB5B mutations may impair electron transfer leading to methemoglobin accumulation | ClinVar: pathogenic variants reported in rare cases |
| Type II methemoglobinemia | Mutations affecting the heme-binding domain reduce enzyme activity | OMIM #613946 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Kidney | 10.2 | Medium |
| Heart | 8.7 | Medium |
| Brain | 6.3 | Low |
| Testis | 5.1 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 14.0 | Hepatocyte line |
| HEK293 | 9.8 | Embryonic kidney |
| K562 | 7.5 | Leukemia line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | missense | <0.01% | Likely loss of start codon; reduced protein expression |
| c.200C>T (p.Thr67Ile) | missense | <0.01% | Impaired heme binding; decreased electron transfer |
Mutation functional classification
Loss of Function (LOF)
Missense mutations in the heme-binding domain reduce electron transfer capacity.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative effects documented.
View complete mutation data：
Gene Ontology (GO)
| • electron transfer activity (GO:0009055) | • heme binding (GO:0020037) |
| • mitochondrial outer membrane (GO:0005741) | • lipid metabolic process (GO:0006629) |
| • fatty acid metabolic process (GO:0006631) |
Pathways
• Fatty acid desaturation (Reactome: R-HSA-8978868)
• Cholesterol biosynthesis (Reactome: R-HSA-191273)
Protein Summary
Cytochrome b5 type B is a 146-amino acid hemoprotein anchored to the outer mitochondrial membrane. It contains a conserved heme-binding domain that transfers electrons from NADH-cytochrome b5 reductase to various acceptors, including fatty acid desaturases and cytochrome P450 enzymes. The protein is essential for lipid metabolism and redox homeostasis.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CYB5B Knockout HEK293 Cell Line | EDJ-KQ9572 | Human | 80777 | Details Get a Quote |
| CYB5B Knockout A-549 Cell Line | EDJ-KQ36381 | Human | 80777 | Details Get a Quote |
| CYB5B Knockout HCT 116 Cell Line | EDJ-KQ36382 | Human | 80777 | Details Get a Quote |
| CYB5B Knockout HeLa Cell Line | EDJ-KQ36383 | Human | 80777 | Details Get a Quote |
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