CHKB Gene: Choline Kinase Beta
Gene encoding choline kinase beta, involved in phospholipid biosynthesis and associated with muscular dystrophy and developmental disorders.
Gene Information Card
| Symbol | CHKB |
|---|---|
| Full Name | Choline Kinase Beta |
| Gene Type | Protein coding |
| Chromosomal Location | 22q13.33 |
| NCBI Gene ID | 1120 ncbi.nlm.nih.gov/gene/1120 |
| Ensembl ID | ENSG00000100288 |
| UniProt ID | Q9Y259 |
| OMIM ID | 602377 |
| HGNC ID | 1937 |
| Aliases | CHK, CHKL, CK, EK, MGC138691, MGC141936 |
Description
The CHKB gene encodes choline kinase beta, an enzyme that catalyzes the first step in phosphatidylcholine biosynthesis: the phosphorylation of choline to phosphocholine. This enzyme is essential for membrane phospholipid production and cell signaling. Mutations in CHKB are associated with autosomal recessive muscular dystrophy with mitochondrial structural abnormalities and developmental delay.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Muscular dystrophy, congenital, with mitochondrial structural abnormalities (MDCMC) | Loss-of-function mutations in CHKB impair phosphatidylcholine synthesis, leading to mitochondrial dysfunction and muscle fiber degeneration. | OMIM #602377; ClinVar |
| Developmental delay, intellectual disability | CHKB deficiency affects neuronal membrane integrity and signaling, contributing to neurodevelopmental phenotypes. | OMIM #602377; ClinVar |
| Rhabdomyosarcoma | Somatic mutations and altered expression of CHKB have been reported in cancer, potentially affecting cell proliferation. | COSMIC |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Skeletal muscle | 12.5 | Medium |
| Heart | 9.8 | Medium |
| Brain | 7.2 | Low |
| Liver | 6.1 | Low |
| Kidney | 5.4 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | 10.3 | Cervical cancer cell line |
| HEK293 | 8.7 | Embryonic kidney cell line |
| K562 | 6.5 | Leukemia cell line |
| A549 | 5.9 | Lung cancer cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.810C>A (p.Tyr270*) | Nonsense | Rare | Loss of function; truncation of protein |
| c.1A>G (p.Met1?) | Start loss | Rare | Loss of function; no translation initiation |
| c.1042C>T (p.Arg348Trp) | Missense | Rare | Likely loss of function; impaired kinase activity |
| c.1222_1223del (p.Leu408fs) | Frameshift | Rare | Loss of function; premature termination |
Mutation functional classification
Loss of Function (LOF)
Most CHKB mutations are loss-of-function, leading to reduced or absent choline kinase activity, impaired phosphatidylcholine synthesis, and mitochondrial dysfunction.
Gain of Function (GOF)
No gain-of-function mutations reported in CHKB.
Dominant Negative (DN)
No dominant-negative mutations reported; inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • choline kinase activity (GO:0004103) | • phosphatidylcholine biosynthetic process (GO:0006656) |
| • cytoplasm (GO:0005737) | • ATP binding (GO:0005524) |
| • phosphorylation (GO:0016310) |
Pathways
• Phosphatidylcholine biosynthesis (Reactome: R-HSA-1483206)
• Glycerophospholipid metabolism (KEGG: hsa00564)
Protein Summary
Choline kinase beta is a 395-amino acid protein that catalyzes the phosphorylation of choline to phosphocholine using ATP. It is a key enzyme in the Kennedy pathway for phosphatidylcholine synthesis. The protein is predominantly cytoplasmic and expressed in multiple tissues, with highest levels in skeletal muscle. Loss of function leads to congenital muscular dystrophy with mitochondrial structural abnormalities.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CHKB Knockout HEK293 Cell Line | EDJ-KQ4272 | Human | 1120 | Details Get a Quote |
| CHKB Knockout A-549 Cell Line | EDJ-KQ26753 | Human | 1120 | Details Get a Quote |
| CHKB Knockout HCT 116 Cell Line | EDJ-KQ26754 | Human | 1120 | Details Get a Quote |
| CHKB Knockout HeLa Cell Line | EDJ-KQ26755 | Human | 1120 | Details Get a Quote |
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