Activates eif2ak2/pkr in the absence of double-stranded RNA (dsRNA), leading to phosphorylation of eif2s1/efi2-alpha and inhibition of translation and induction of apoptosis. Required for siRNA production by dicer1 and for subsequent siRNA-mediated post- transcriptional gene silencing. Does not seem to be required for processing of pre-miRNA to miRNA by dicer1 (By similarity). {By
Similarity}.