EIF3B
Eukaryotic Translation Initiation Factor 3 Subunit B
Gene Information Card
| Symbol | EIF3B |
|---|---|
| Full Name | Eukaryotic Translation Initiation Factor 3 Subunit B |
| Gene Type | protein-coding |
| Chromosomal Location | 7p22.3 |
| NCBI Gene ID | 8669 ncbi.nlm.nih.gov/gene/8669 |
| Ensembl ID | ENSG00000106211 |
| UniProt ID | P55884 |
| OMIM ID | 603917 |
| HGNC ID | 3270 |
| Aliases | EIF3S9, PRT1, eIF3-p116, eIF3-eta |
Description
EIF3B encodes a subunit of the eukaryotic translation initiation factor 3 (eIF3) complex, which is essential for the initiation of protein synthesis. The eIF3 complex binds to the 40S ribosomal subunit and promotes the formation of the 43S pre-initiation complex. EIF3B is involved in mRNA recruitment, scanning, and start codon selection. Dysregulation of EIF3B has been implicated in various cancers and developmental disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Breast cancer | Overexpression of EIF3B enhances translation of oncogenic mRNAs, promoting cell proliferation and tumor growth. | PMID: 23555292 |
| Hepatocellular carcinoma | Upregulation of EIF3B correlates with poor prognosis and increased tumor invasion. | PMID: 25634884 |
| Colorectal cancer | EIF3B overexpression drives translation of cyclin D1 and c-Myc, contributing to tumorigenesis. | PMID: 26921324 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Testis | 34.2 | High |
| Lymph node | 22.1 | Medium |
| Brain | 18.5 | Medium |
| Liver | 12.3 | Low |
| Heart | 9.8 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HEK293 | 28.5 | High expression |
| HeLa | 25.1 | High expression |
| MCF7 | 20.3 | Medium expression |
| HepG2 | 18.7 | Medium expression |
| A549 | 15.2 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1234G>A (p.Gly412Arg) | Missense | 0.01% (gnomAD) | Unknown functional impact |
| c.567_569del (p.Lys189del) | In-frame deletion | 0.001% (COSMIC) | Potential loss of eIF3 complex stability |
| c.2101C>T (p.Arg701Trp) | Missense | 0.005% (ClinVar) | Reported in breast cancer; uncertain significance |
Mutation functional classification
Loss of Function (LOF)
Rare truncating mutations (e.g., frameshift or nonsense) are predicted to impair eIF3 complex assembly and translation initiation, potentially leading to reduced cell growth.
Gain of Function (GOF)
Amplification or overexpression of EIF3B is observed in multiple cancers, leading to enhanced translation of pro-proliferative mRNAs.
Dominant Negative (DN)
No well-characterized dominant-negative mutations have been reported for EIF3B.
View complete mutation data：
Gene Ontology (GO)
Pathways
• hsa03013 - RNA transport
• hsa04141 - Protein processing in endoplasmic reticulum
• hsa05200 - Pathways in cancer
Protein Summary
EIF3B is a 116 kDa protein that serves as a core scaffold of the eIF3 complex. It contains multiple WD40 repeats that mediate protein-protein interactions within the complex. The protein is essential for the recruitment of the 43S pre-initiation complex to mRNA and for scanning the 5' UTR to locate the start codon. Post-translational modifications, including phosphorylation, regulate its activity and stability.
Related Services
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|---|---|---|---|---|
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