SSR1 (Signal Sequence Receptor Subunit 1)
A key component of the translocon complex involved in protein translocation across the endoplasmic reticulum membrane.
Gene Information Card
| Symbol | SSR1 |
|---|---|
| Full Name | Signal Sequence Receptor Subunit 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 6p24.3 |
| NCBI Gene ID | 6745 ncbi.nlm.nih.gov/gene/6745 |
| Ensembl ID | ENSG00000124784 |
| UniProt ID | P43307 |
| OMIM ID | 600868 |
| HGNC ID | 11322 |
| Aliases | TRAP-alpha, SSR-alpha |
Description
SSR1 encodes the alpha subunit of the signal sequence receptor (SSR), a glycosylated endoplasmic reticulum (ER) membrane protein. The SSR complex, also known as the translocon-associated protein (TRAP) complex, is essential for the translocation of nascent polypeptides across the ER membrane. SSR1 specifically binds signal sequences and facilitates the proper insertion and processing of secreted and membrane proteins.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Congenital disorder of glycosylation (CDG) | Mutations in SSR1 impair protein translocation and glycosylation, leading to multisystem disease. | ClinVar, OMIM |
| Cancer (various) | Altered SSR1 expression may affect tumor cell protein secretion and survival. | COSMIC, NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Pancreas | 50.2 | High |
| Liver | 38.1 | High |
| Kidney | 35.7 | High |
| Brain | 28.4 | Medium |
| Heart | 22.6 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 62.3 | Hepatocellular carcinoma |
| K562 | 45.1 | Leukemia |
| HeLa | 40.8 | Cervical adenocarcinoma |
| A549 | 38.2 | Lung carcinoma |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1A>G (p.Met1?) | Missense | Rare | Loss of start codon, likely loss of function |
| c.404C>T (p.Pro135Leu) | Missense | Rare | Impaired protein translocation |
| c.715G>A (p.Gly239Arg) | Missense | Rare | Unknown functional effect |
Mutation functional classification
Loss of Function (LOF)
Mutations that disrupt SSR1 translation or folding lead to reduced protein translocation efficiency.
Gain of Function (GOF)
Not reported.
Dominant Negative (DN)
Not reported.
View complete mutation data：
Gene Ontology (GO)
| • signal sequence binding (GO:0005047) | • endoplasmic reticulum (GO:0005783) |
| • endoplasmic reticulum membrane (GO:0005789) | • SRP-dependent cotranslational protein targeting to membrane (GO:0006614) |
| • integral component of membrane (GO:0016021) |
Pathways
• Protein processing in endoplasmic reticulum (KEGG: hsa04141)
• SRP-dependent cotranslational protein targeting to membrane (Reactome: R-HSA-1799339)
Protein Summary
SSR1 (TRAP-alpha) is a 286-amino acid transmembrane protein with a large luminal domain that binds signal sequences. It forms a heterotetrameric complex with SSR2, SSR3, and SSR4. The complex stabilizes the ribosome-translocon junction and ensures efficient protein translocation. SSR1 is ubiquitously expressed and essential for normal cellular function.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SSR1 Knockout HEK293 Cell Line | EDJ-KQ5851 | Human | 6745 | Details Get a Quote |
| SSR1 Knockout A-549 Cell Line | EDJ-KQ29315 | Human | 6745 | Details Get a Quote |
| SSR1 Knockout HCT 116 Cell Line | EDJ-KQ29316 | Human | 6745 | Details Get a Quote |
| SSR1 Knockout HeLa Cell Line | EDJ-KQ29317 | Human | 6745 | Details Get a Quote |
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