PCYT1B
Phosphate Cytidylyltransferase 1B, Choline
Gene Information Card
| Symbol | PCYT1B |
|---|---|
| Full Name | Phosphate Cytidylyltransferase 1B, Choline |
| Gene Type | protein-coding |
| Chromosomal Location | Xp22.11 |
| NCBI Gene ID | 9468 ncbi.nlm.nih.gov/gene/9468 |
| Ensembl ID | ENSG00000102081 |
| UniProt ID | Q9Y5K3 |
| OMIM ID | 300611 |
| HGNC ID | 8755 |
| Aliases | CTP:phosphocholine cytidylyltransferase beta, CCTB, CTPCTB |
Description
PCYT1B encodes the beta isoform of choline-phosphate cytidylyltransferase, a key enzyme in the CDP-choline pathway for phosphatidylcholine biosynthesis. This enzyme catalyzes the rate-limiting step: conversion of phosphocholine and CTP to CDP-choline and pyrophosphate. The gene is located on the X chromosome and is expressed in various tissues, with highest levels in brain and testis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Intellectual disability (X-linked) | Loss-of-function mutations in PCYT1B impair phosphatidylcholine synthesis, affecting neuronal membrane biogenesis and signaling. | ClinVar: pathogenic variants reported in families with X-linked intellectual disability. |
| Developmental delay | Disruption of PCYT1B leads to reduced CDP-choline levels, impacting neurodevelopment. | OMIM: 300611 associated with intellectual disability and developmental delay. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | High |
| Testis | 8.3 | Medium |
| Heart | 4.1 | Low |
| Liver | 2.0 | Low |
| Kidney | 3.5 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 15.2 | High expression in embryonic kidney cells |
| SH-SY5Y | 18.7 | Neuroblastoma cell line, high expression |
| HeLa | 6.8 | Cervical carcinoma, moderate expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.586C>T (p.Arg196*) | Nonsense | Rare | Loss of function; truncated protein lacking catalytic domain |
| c.1012G>A (p.Gly338Arg) | Missense | Rare | Likely loss of function; reduced enzyme activity |
Mutation functional classification
Loss of Function (LOF)
Nonsense and missense variants that reduce or abolish CTP:phosphocholine cytidylyltransferase activity, leading to decreased phosphatidylcholine synthesis.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations reported.
View complete mutation data：
Gene Ontology (GO)
| • choline-phosphate cytidylyltransferase activity (GO:0004105) | • phosphatidylcholine biosynthetic process (GO:0006656) |
| • cytoplasm (GO:0005737) | • cytosol (GO:0005829) |
Pathways
• CDP-choline pathway (phosphatidylcholine biosynthesis)
• Glycerophospholipid metabolism
Protein Summary
PCYT1B encodes a 367-amino acid protein (UniProt Q9Y5K3) that functions as a homodimer. It contains a catalytic domain and a membrane-binding amphipathic helix. The enzyme is regulated by lipid activators and phosphorylation. It is essential for membrane phospholipid homeostasis, particularly in neurons.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| PCYT1B Knockout HEK293 Cell Line | EDJ-KQ6596 | Human | 9468 | Details Get a Quote |
| PCYT1B Knockout HeLa Cell Line | EDJ-KQ55173 | Human | 9468 | Details Get a Quote |
| PCYT1B Knockout A-549 Cell Line | EDJ-KQ63653 | Human | 9468 | Details Get a Quote |
| PCYT1B Knockout HCT 116 Cell Line | EDJ-KQ72113 | Human | 9468 | Details Get a Quote |
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