SAA2-SAA4 readthrough
Serum Amyloid A2-Serum Amyloid A4 readthrough transcript
Gene Information Card
| Symbol | SAA2-SAA4 |
|---|---|
| Full Name | SAA2-SAA4 readthrough |
| Gene Type | readthrough transcript |
| Chromosomal Location | 11p15.1 |
| NCBI Gene ID | 100526823 ncbi.nlm.nih.gov/gene/100526823 |
| Ensembl ID | ENSG00000272398 |
| UniProt ID | P0DJI8 |
| OMIM ID | - |
| HGNC ID | 44097 |
| Aliases | SAA2-SAA4 fusion, SAA2-SAA4 readthrough transcript |
Description
SAA2-SAA4 is a naturally occurring readthrough transcript that spans the SAA2 and SAA4 genes on chromosome 11p15.1. This transcript produces a fusion protein combining sequences from serum amyloid A2 (acute phase) and serum amyloid A4 (constitutive). The readthrough is supported by NCBI and Ensembl annotations. SAA proteins are apolipoproteins of HDL, involved in acute phase response, cholesterol transport, and amyloid deposition.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Reactive systemic amyloidosis (AA amyloidosis) | SAA2-SAA4 readthrough may contribute to amyloid fibril formation; SAA2 is a major acute phase precursor of AA amyloid | ClinVar, OMIM |
| Familial Mediterranean fever | Elevated SAA levels due to inflammation; SAA2-SAA4 readthrough may modulate amyloid risk | NCBI Gene, OMIM |
| Rheumatoid arthritis | Chronic inflammation increases SAA2 expression; readthrough may alter HDL function | NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | High | High |
| Adipose tissue | Medium | Medium |
| Spleen | Medium | Medium |
| Lung | Low | Low |
| Kidney | Low | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | High | Hepatocyte cell line |
| THP-1 | Medium | Monocyte/macrophage |
| A549 | Low | Lung epithelial |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G | SNV | Not reported | Unknown |
| c.123C>T | SNV | Not reported | Unknown |
Mutation functional classification
Loss of Function (LOF)
No loss-of-function mutations reported for SAA2-SAA4 readthrough.
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)
| • acute-phase response (GO:0006953) | • high-density lipoprotein particle (GO:0034364) |
| • lipid transporter activity (GO:0005319) | • cholesterol binding (GO:0015485) |
Pathways
• ['Acute phase response (Reactome: R-HSA-6783783)']
• ['HDL remodeling (Reactome: R-HSA-8963896)']
• ['Amyloid fiber formation (Reactome: R-HSA-977225)']
Protein Summary
The SAA2-SAA4 readthrough protein is a fusion of serum amyloid A2 (104 aa) and serum amyloid A4 (112 aa) sequences. It is predicted to retain the N-terminal signal peptide and lipid-binding properties of SAA2, with C-terminal contributions from SAA4. The protein is secreted and associates with HDL particles, playing roles in acute phase response and cholesterol transport. Its readthrough nature may generate isoforms with altered amyloidogenic potential.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SAA2-SAA4 Knockout HEK293 Cell Line | EDJ-KQ52485 | Human | 100528017 | Details Get a Quote |
| SAA2-SAA4 Knockout HeLa Cell Line | EDJ-KQ60948 | Human | 100528017 | Details Get a Quote |
| SAA2-SAA4 Knockout A-549 Cell Line | EDJ-KQ69423 | Human | 100528017 | Details Get a Quote |
| SAA2-SAA4 Knockout HCT 116 Cell Line | EDJ-KQ77774 | Human | 100528017 | Details Get a Quote |
