O75569

PACT also known as PRKRA is a protein kinase activated by double-stranded RNA which mediates the effects of interferon in response to viral infection. PACT plays a crucial role in cellular response to stress by activating protein kinase PKR. This activation leads to eIF2α phosphorylation, which inhibits protein translation and can trigger apoptosis, making PACT an important player in regulating cell survival under adverse conditions. PACT can directly bind to double-stranded RNA, although pro-apoptotic function is enhanced in absence of dsRNA. Growth factors can inhibit PACT′s apoptotic activity, highlighting regulatory role in cell fate decisions. In human and mouse cells, PACT undergoes phosphorylation at Serine 18, and this phosphorylated form is essential for PKR activation following stress. PACT may form a heterodimer with eIF2α, interacting through double-stranded RNA binding motif domain, which underscores significance in stress response pathway.