EIF2A encodes a translation initiation factor that is distinct from the canonical eIF2 complex. While eIF2 delivers the initiator tRNA in a GTP-dependent manner, EIF2A can deliver it independently and is particularly important under stress conditions, including viral infection and ER stress relevant to neurodegeneration.
EIF2A (Eukaryotic Translation Initiation Factor 2A) is a member of the eIF2 family but has distinct functions. Unlike the canonical eIF2 (eIF2α, eIF2β, eIF2γ), EIF2A functions as a single polypeptide that can initiate translation in a non-canonical manner. It is particularly important under stress conditions when general translation is suppressed.
| Property |
Value |
| Gene Symbol |
EIF2A |
| Full Name |
Eukaryotic Translation Initiation Factor 2A |
| Chromosomal Location |
3q27.1 |
| NCBI Gene ID |
27185 |
| OMIM ID |
609994 |
| Ensembl ID |
ENSG00000144895 |
| UniProt ID |
Q9Y5Q3 |
| Encoded Protein |
eIF2A |
| Associated Diseases |
Alzheimer's disease, Parkinson's disease, viral encephalitis, liver disease |
EIF2A has distinct functions from canonical eIF2:
- Delivers Met-tRNAi to the ribosome independently of GTP
- Can bypass eIF2-alpha phosphorylation inhibition
- Important when general translation is shut down
- Preferred initiation factor for certain mRNAs
- Activated during viral infection
- Important for ER stress response translation
- May help express stress-response proteins
- Integrated with unfolded protein response (UPR)
- Some viral RNAs use eIF2A
- Cellular mRNAs with complex 5' UTRs
- mRNAs encoding stress response proteins
- ER stress is a feature of AD neurons
- eIF2A may help express protective proteins
- Translation dysregulation is common in AD
- eIF2A phosphorylation status affects AD pathology
- ER stress contributes to dopaminergic neuron death
- eIF2A may modulate survival pathways
- Unfolded protein response involvement
- eIF2A is important for antiviral translation
- Some viruses exploit eIF2A pathway
- Neurotropic viruses affect neurons
EIF2A has widespread expression:
- Highest expression: Liver, pancreas, brain
- Ubiquitous: Most tissues
- Cellular localization: Cytoplasmic
In the brain:
- Expressed in neurons and glia
- Higher expression in metabolically active regions
- Upregulated under stress conditions
- Kim & Kim, EIF2A: a non-canonical translation initiation factor (2011)
- Grosely et al., The eIF2A homolog eIF2A in stress response (2015)
- Hinnebusch, The scanning mechanism of eukaryotic translation initiation (2014)
- Baird & Wek, EIF2 and translational control in disease (2012)