FIG 7.

Model depicting different patterns of p38 localization depending on the presence or absence of Piwil2. (A) In WT epithelial cancer cells (at least HeLa and HepG2), Piwil2 recruits p38 to K8, increases the phosphorylation of K8, and protects K8 from degradation. As a result, K8 accumulation protects cells from Fas-mediated apoptosis. Another effect of the K8/Piwil2/p38 complex is to decrease the interaction of p38 with p53. (B) While in Piwil2 knockdown cells, p38 phosphorylates p53 rather than K8, increasing FasL sensitivity and p53-induced apoptosis.