Dear Rana,

Do you mean other factors beside AA deficiency may activate GCN2?

Hi Mr. Karimi,

So its known that GCN2 is a serine/threonine-protein kinase that senses amino acid deficiency through binding to uncharged transfer RNA (tRNA). Protein kinase GCN2 is a multidomain protein and its C-terminus contains a region homologous to histidyl-tRNA synthetase (HisRS) next to the kinase catalytic moiety.[2] This HisRS-like region forms a dimer and dimerization is required for GCN2 function. The crucial contribution to GCN2 function is the promotion of tRNA binding and the stimulation of the kinase domain via physical interaction. 

So, is there other factor that can activate GCN2, and does GCN2 have other domains that these factors can bind to?

UV radiation in addition to AA deficiency.

Also see https://elifesciences.org/content/5/e14295