Translation initiation factor eIF-2B subunit alpha
Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
Acts as a non-essential regulatory component of the translation initiation factor 2B (eIF2-B or GCD complex), which catalyzes the exchange of eukaryotic initiation factor 2 (eIF-2)-bound GDP for GTP and is regulated by phosphorylated eIF-2. It activates the synthesis of GCN4 in yeast under amino acid starvation conditions by suppressing the inhibitory effects of multiple AUG codons present in the leader of GCN4 mRNA. It may promote either repression or activation of GCN4 expression depending on amino acid availability. Modulation of GCN3 regulatory function in response to amino acid availability occurs post-translationally.
Belongs to the eIF-2B alpha/beta/delta subunits family.