eIF2B

eIF2B is a protein found in eukaryotes. It is the guanine nucleotide exchange factor for the eukaryotic initiation factor 2 and therefore converts the inactive eIF2-GDP to the active eIF2-GTP. This activation is hindered by phosphorylation of the alpha subunit of eIF2 and therefore inhibits translation initiation.

Human genes which encode eIF-2B proteins include:

• EIF2B1 – alpha subunit
• EIF2B2 – beta subunit
• EIF2B3 – gamma subunit
• EIF2B4 – delta subunit
• EIF2B5 – epsilon subunit