ITPK1: Inositol-Tetrakisphosphate 1-Kinase
A key regulator of inositol phosphate metabolism and calcium signaling
Gene Information Card
| Symbol | ITPK1 |
|---|---|
| Full Name | Inositol-Tetrakisphosphate 1-Kinase |
| Gene Type | Protein coding |
| Chromosomal Location | 14q31.1 |
| NCBI Gene ID | 3705 ncbi.nlm.nih.gov/gene/3705 |
| Ensembl ID | ENSG00000100605 |
| UniProt ID | Q13572 |
| OMIM ID | 601838 |
| HGNC ID | 6178 |
| Aliases | IP4K, IP4-kinase, ITPK1alpha, ITPK1beta |
Description
ITPK1 encodes inositol-tetrakisphosphate 1-kinase, an enzyme that phosphorylates inositol 1,3,4-trisphosphate (Ins(1,3,4)P3) to inositol 1,3,4,5-tetrakisphosphate (Ins(1,3,4,5)P4). This protein plays a critical role in inositol phosphate metabolism, calcium signaling, and cellular signal transduction. Alternative splicing generates multiple isoforms.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Spinocerebellar ataxia type 29 (SCA29) | Missense mutations in ITPK1 impair kinase activity, disrupting inositol phosphate homeostasis and Purkinje cell function. | ClinVar, OMIM |
| Intellectual disability | De novo loss-of-function variants associated with neurodevelopmental phenotypes. | ClinVar, NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Cerebellum | 18.3 | High |
| Testis | 8.2 | Medium |
| Heart | 6.1 | Low |
| Liver | 4.3 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 10.1 | Moderate expression |
| SH-SY5Y | 14.7 | High expression |
| HeLa | 7.8 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.106G>A (p.Gly36Arg) | Missense | Rare | Reduced kinase activity; associated with SCA29 |
| c.497C>T (p.Thr166Met) | Missense | Rare | Impaired substrate binding; neurodevelopmental phenotype |
| c.1A>G (p.Met1Val) | Start loss | Very rare | Loss of protein expression |
Mutation functional classification
Loss of Function (LOF)
Missense variants (e.g., p.Gly36Arg) reduce catalytic activity, leading to inositol phosphate imbalance.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Inositol phosphate metabolism (KEGG: hsa00562)
• Phosphatidylinositol signaling system (KEGG: hsa04070)
Protein Summary
ITPK1 is a 414-amino acid protein (isoform 1) with a molecular weight of ~47 kDa. It contains an inositol polyphosphate kinase domain and is predominantly cytoplasmic. The enzyme converts Ins(1,3,4)P3 to Ins(1,3,4,5)P4, a precursor for higher inositol phosphates. It is highly expressed in brain, especially cerebellum, and is essential for neuronal calcium signaling.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| ITPK1 Knockout HEK293 Cell Line | EDJ-KQ1683 | Human | 3705 | Details Get a Quote |
| ITPK1 Knockout A-549 Cell Line | EDJ-KQ21468 | Human | 3705 | Details Get a Quote |
| ITPK1 Knockout HCT 116 Cell Line | EDJ-KQ21469 | Human | 3705 | Details Get a Quote |
| ITPK1 Knockout HeLa Cell Line | EDJ-KQ21470 | Human | 3705 | Details Get a Quote |
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