EIF2S1

EIF2S1, also known as eukaryotic translation initiation factor 2 subunit alpha, is a protein-coding gene. It plays a crucial role in the regulation of protein synthesis, a fundamental process in all living cells. Specifically, EIF2S1 is a subunit of eukaryotic initiation factor 2 (eIF2), a heterotrimeric complex essential for the initiation of translation. This complex binds to initiator tRNA carrying methionine and then to the small ribosomal subunit, facilitating the assembly of the translation initiation complex on messenger RNA (mRNA).

The activity of EIF2S1 is tightly regulated by phosphorylation. When EIF2S1 is phosphorylated, it binds more strongly to a guanine nucleotide exchange factor (GEF) called EIF2B. This interaction sequesters EIF2B, thereby inhibiting the recycling of eIF2 from its GDP-bound to its GTP-bound form. This leads to a global decrease in protein synthesis. This regulatory mechanism is a key cellular response to various stress conditions, including amino acid starvation, endoplasmic reticulum stress, and viral infection.

Mutations in the EIF2S1 gene have been associated with certain human diseases. For example, mutations in EIF2S1 have been linked to Pelizaeus-Merzbacher disease, a severe neurological disorder affecting myelin formation in the brain. Research into EIF2S1 continues to unravel its complex roles in cellular physiology and its involvement in disease pathogenesis.