INPP5B
Inositol Polyphosphate-5-Phosphatase B
Gene Information Card
| Symbol | INPP5B |
|---|---|
| Full Name | Inositol Polyphosphate-5-Phosphatase B |
| Gene Type | protein-coding |
| Chromosomal Location | 1p34.3 |
| NCBI Gene ID | 3633 ncbi.nlm.nih.gov/gene/3633 |
| Ensembl ID | ENSG00000116285 |
| UniProt ID | P32019 |
| OMIM ID | 147410 |
| HGNC ID | 6077 |
| Aliases | 5PTase, OCRL2, PIB5PA |
Description
INPP5B encodes a member of the inositol polyphosphate-5-phosphatase family. The enzyme hydrolyzes the 5-phosphate from inositol 1,4,5-trisphosphate (Ins(1,4,5)P3) and phosphatidylinositol 4,5-bisphosphate (PIP2), thereby regulating phosphoinositide signaling and intracellular trafficking. INPP5B is ubiquitously expressed and shares functional homology with OCRL (Lowe syndrome protein).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Lowe syndrome (oculocerebrorenal syndrome) | Loss-of-function mutations in OCRL cause Lowe syndrome; INPP5B can partially compensate for OCRL deficiency, but its role in disease is indirect. | OMIM #309000; functional studies show INPP5B overexpression rescues OCRL defects in cell models. |
| Dent disease 2 | Mutations in OCRL cause Dent disease 2; INPP5B may modulate phenotype severity. | ClinVar; literature review. |
| Cancer (general) | Altered INPP5B expression may affect PI3K/AKT signaling in tumors. | COSMIC; TCGA data. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Kidney | 15.3 | Medium |
| Liver | 8.7 | Low |
| Testis | 20.1 | High |
| Lung | 10.2 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 18.4 | High expression |
| HeLa | 14.2 | Medium expression |
| HepG2 | 9.8 | Low expression |
| K562 | 22.1 | High expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1003C>T (p.Arg335Trp) | missense | 0.01% (gnomAD) | Reduced phosphatase activity in vitro |
| c.1456G>A (p.Glu486Lys) | missense | 0.005% (gnomAD) | Unknown functional effect |
| c.1742_1743del (p.Glu581Valfs*12) | frameshift | Rare | Loss of function |
Mutation functional classification
Loss of Function (LOF)
Frameshift and nonsense variants that truncate the catalytic domain lead to loss of phosphatase activity.
Gain of Function (GOF)
No gain-of-function mutations reported.
Dominant Negative (DN)
No dominant-negative mutations characterized.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Phosphatidylinositol phosphate metabolism (Reactome: R-HSA-1483255)
• PI3K/AKT signaling (KEGG: hsa04151)
• Inositol phosphate metabolism (KEGG: hsa00562)
Protein Summary
INPP5B is a 100 kDa inositol polyphosphate-5-phosphatase that localizes to the cytosol and membrane. It contains an N-terminal PH domain and a central 5-phosphatase catalytic domain. The enzyme dephosphorylates PIP2 and Ins(1,4,5)P3, modulating calcium signaling and vesicular trafficking. INPP5B is ubiquitously expressed and functionally overlaps with OCRL.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| INPP5B Knockout HEK293 Cell Line | EDJ-KQ1654 | Human | 3633 | Details Get a Quote |
| INPP5B Knockout HeLa Cell Line | EDJ-KQ20052 | Human | 3633 | Details Get a Quote |
| INPP5B Knockout A-549 Cell Line | EDJ-KQ21400 | Human | 3633 | Details Get a Quote |
| INPP5B Knockout HCT 116 Cell Line | EDJ-KQ21401 | Human | 3633 | Details Get a Quote |
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