Activating transcription factor 4
is an important component of UPR-PERK pathway.
Because activating transcription factor 4
(ATF4) and ATF6 have been reported to be responsible for transcription of the Grp78 gene (Luo et al.
Instead, mTORC1 contribution to purine synthesis occurs through the induction of the activating transcription factor 4
(ATF4) that in turn triggers methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 2, methenyltetrahydrofolate cyclohydrolase (MTHFD2) expression, a key component of the mitochondrial tetrahydrofolate cycle  (Figure 1(c)).
Western blotting showed up-regulation of CRT, Nrf2, activating transcription factor 4
(ATF4), CHOP and caspase-12 expression after H/R.
In addition to reducing translation, PERK-mediated phosphorylation of eIF2[alpha] also induces preferential translation of activating transcription factor 4
(ATF4), a transcription activator of the integrated stress response .