SMPDL3B
Sphingomyelin Phosphodiesterase Acid Like 3B
Gene Information Card
| Symbol | SMPDL3B |
|---|---|
| Full Name | Sphingomyelin Phosphodiesterase Acid Like 3B |
| Gene Type | protein-coding |
| Chromosomal Location | 1p35.3 |
| NCBI Gene ID | 27293 ncbi.nlm.nih.gov/gene/27293 |
| Ensembl ID | ENSG00000130768 |
| UniProt ID | Q92484 |
| OMIM ID | 610221 |
| HGNC ID | 11138 |
| Aliases | SMPDL3B, ASML3B, ASM-like 3B, acid sphingomyelinase-like phosphodiesterase 3b |
Description
SMPDL3B encodes a member of the acid sphingomyelinase-like phosphodiesterase family. The protein is involved in sphingolipid metabolism, specifically catalyzing the hydrolysis of sphingomyelin to ceramide and phosphocholine. It is expressed in kidney podocytes and plays a role in maintaining glomerular filtration barrier integrity. Mutations in SMPDL3B are associated with steroid-resistant nephrotic syndrome.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Steroid-resistant nephrotic syndrome (SRNS) | Loss-of-function mutations impair podocyte function, leading to proteinuria and kidney disease. | ClinVar, OMIM |
| Focal segmental glomerulosclerosis (FSGS) | Deficient SMPDL3B activity disrupts sphingolipid signaling in podocytes, contributing to glomerular scarring. | NCBI Gene, PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | 12.5 | Medium |
| Liver | 8.3 | Low |
| Lung | 6.1 | Low |
| Brain | 4.2 | Low |
| Heart | 3.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Podocytes (immortalized) | 15.0 | High expression; key for function |
| HEK293 | 9.5 | Moderate expression |
| HepG2 | 7.2 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.103C>T (p.Arg35Ter) | Nonsense | Rare | Loss of function; associated with SRNS |
| c.467G>A (p.Arg156His) | Missense | Rare | Reduced enzymatic activity; reported in FSGS |
| c.832C>T (p.Arg278Cys) | Missense | Rare | Impaired protein stability; linked to nephrotic syndrome |
Mutation functional classification
Loss of Function (LOF)
Nonsense and missense mutations (e.g., p.Arg35Ter, p.Arg156His) reduce or abolish sphingomyelinase activity, leading to podocyte dysfunction.
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)
| • sphingomyelin phosphodiesterase activity | • ceramide biosynthetic process |
| • sphingolipid metabolic process | • plasma membrane |
| • lysosome |
Pathways
• Sphingolipid metabolism
• Ceramide signaling pathway
Protein Summary
SMPDL3B is a 453-amino acid protein with a signal peptide and a conserved acid sphingomyelinase-like domain. It localizes to the plasma membrane and lysosomes, where it hydrolyzes sphingomyelin to generate ceramide, a key signaling lipid. In podocytes, SMPDL3B regulates cytoskeletal dynamics and cell survival. Loss of function leads to altered sphingolipid homeostasis and kidney disease.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SMPDL3B Knockout HEK293 Cell Line | EDJ-KQ8749 | Human | 27293 | Details Get a Quote |
| SMPDL3B Knockout A-549 Cell Line | EDJ-KQ34995 | Human | 27293 | Details Get a Quote |
| SMPDL3B Knockout HCT 116 Cell Line | EDJ-KQ34996 | Human | 27293 | Details Get a Quote |
| SMPDL3B Knockout HeLa Cell Line | EDJ-KQ56050 | Human | 27293 | Details Get a Quote |
