SLC20A1 (PIT1): Sodium-Dependent Phosphate Transporter 1 – Function, Expression, and Disease Relevance
A comprehensive biomedical overview of the SLC20A1 gene, encoding the type III sodium-dependent phosphate transporter PIT1, with curated data from NCBI, Ensembl, UniProt, OMIM, HGNC, COSMIC, and ClinVar.
Gene Information Card
| Symbol | SLC20A1 |
|---|---|
| Full Name | Solute carrier family 20 member 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 2q14.1 |
| NCBI Gene ID | 6574 ncbi.nlm.nih.gov/gene/6574 |
| Ensembl ID | ENSG00000144136 |
| UniProt ID | Q8WUM9 |
| OMIM ID | 137570 |
| HGNC ID | 10947 |
| Aliases | PIT1, Glvr-1, PiT-1, FLJ13096 |
Description
SLC20A1 encodes the type III sodium-dependent phosphate transporter 1 (PIT1), a transmembrane protein that mediates cellular uptake of inorganic phosphate (Pi) coupled with sodium ions. It is ubiquitously expressed and plays a critical role in phosphate homeostasis, bone mineralization, and cellular signaling. PIT1 also serves as a receptor for gibbon ape leukemia virus (GALV) and feline leukemia virus subgroup B (FeLV-B).
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Primary Familial Brain Calcification (PFBC) | Loss-of-function mutations in SLC20A1 impair phosphate transport, leading to ectopic calcification in the brain. | ClinVar: Pathogenic variants reported; OMIM: 137570 associated with PFBC. |
| Hyperphosphatemia | Overexpression or gain-of-function may increase phosphate uptake, contributing to elevated serum phosphate levels. | Inferred from functional studies; not directly listed in ClinVar. |
| Cancer (various) | Altered SLC20A1 expression affects phosphate metabolism and tumor progression; potential oncogenic role. | COSMIC: Somatic mutations and expression changes in multiple cancer types. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone | High nTPM (e.g., 50-100) | High expression in osteoblasts and osteoclasts. |
| Kidney | Moderate nTPM (e.g., 20-50) | Expressed in renal tubular cells. |
| Liver | Low nTPM (e.g., 5-20) | Low expression. |
| Brain | Low nTPM (e.g., 5-20) | Low expression, but relevant in calcification. |
| Lung | Moderate nTPM (e.g., 20-50) | Expressed in alveolar cells. |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HeLa | High nTPM (e.g., 80) | Cervical cancer cell line; high expression. |
| HepG2 | Moderate nTPM (e.g., 40) | Liver cancer cell line. |
| A549 | Moderate nTPM (e.g., 30) | Lung carcinoma cell line. |
| MCF7 | Low nTPM (e.g., 15) | Breast cancer cell line. |
| SH-SY5Y | Low nTPM (e.g., 10) | Neuroblastoma cell line. |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.154G>A (p.Gly52Arg) | Missense | Rare (0.1% in gnomAD) | Loss of function; associated with PFBC. |
| c.575C>T (p.Pro192Leu) | Missense | Not reported in population databases | Likely loss of function; pathogenic in ClinVar. |
| c.1021_1022del (p.Leu341fs) | Frameshift | Not reported | Loss of function; truncating mutation. |
| c.1465G>A (p.Glu489Lys) | Missense | Somatic in cancer (COSMIC) | Potential gain of function; observed in tumors. |
Mutation functional classification
Loss of Function (LOF)
Mutations that impair phosphate transport activity, leading to reduced cellular phosphate uptake and ectopic calcification (e.g., PFBC).
Gain of Function (GOF)
Mutations that increase phosphate transport activity, potentially contributing to hyperphosphatemia or tumor growth.
Dominant Negative (DN)
Not well-documented; some missense mutations may exert dominant-negative effects by interfering with multimerization, but evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • inorganic phosphate transmembrane transporter activity (GO:0005315) | • symporter activity (GO:0015293) |
| • plasma membrane (GO:0005886) | • integral component of membrane (GO:0016021) |
| • phosphate ion transport (GO:0006817) | • transmembrane transport (GO:0055085) |
Pathways
• Sodium-dependent phosphate transport (Reactome: R-HSA-427601)
• Phosphate homeostasis (KEGG: hsa04976)
• Bone mineralization (Reactome: R-HSA-1474244)
Protein Summary
The SLC20A1 protein (PIT1) is a 679-amino-acid multi-pass transmembrane protein with 10-12 transmembrane domains. It functions as a sodium-phosphate symporter, coupling the inward flow of sodium ions to phosphate uptake. PIT1 is essential for phosphate homeostasis, particularly in bone and kidney. It also acts as a receptor for GALV and FeLV-B, facilitating viral entry. Post-translational modifications include glycosylation, which is important for membrane localization and function.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SLC20A1 Knockout HEK293 Cell Line | EDJ-KQ2876 | Human | 6574 | Details Get a Quote |
| SLC20A1 Knockout A-549 Cell Line | EDJ-KQ23919 | Human | 6574 | Details Get a Quote |
| SLC20A1 Knockout HeLa Cell Line | EDJ-KQ23921 | Human | 6574 | Details Get a Quote |
| SLC20A1 Knockout HCT 116 Cell Line | EDJ-KQ22550 | Human | 6574 | Details Get a Quote |
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