Figure 7. Suppression of BiP by β-arrestin-2 leads to the release of BIK. (A) Silencing of β-arrestin-2 had no effect on BIK levels in DMSO- or LPS-treated cells. (B) Overexpression of β-arrestin-2 increased BIK levels in LPS-stimulated cells, but not in DMSO-treated cells. (C) Silencing of β-arrestin-2 had no effect on BIK levels in thapsigargin (THAP)-stimulated cells. (D) Overexpression of β-arrestin-2 increased BIK levels in THAP-stimulated cells. (E) Co-expression of BiP attenuated BIK release in β-arrestin-2- overexpressing LPS-stimulated cells. (F) HA15 further upregulated BIK in β-arrestin-2-overexpressing LPS-stimulated cells. (G) Overexpression of β-arrestin-2 was associated with high levels of BIK in premature mice and humans. (H) β-arrestin-2 activated a BIK luciferase reporter (P<0.05).