PAN3
PAN3 belongs to the mRNA turnover machinery rather than to a signaling cascade. It is the obligate partner of the deadenylase PAN2, and together they form the cytoplasmic poly(A)-specific deadenylation complex that shortens poly(A) tails before the CCR4-NOT complex completes decay. PAN3 supplies a C3H1-type zinc finger for RNA and PAN2 binding and a protein kinase-like domain whose catalytic motifs are degenerate, so whether it phosphorylates anything remains uncertain and it is usually treated as a pseudokinase scaffold. Through PAN2-PAN3, the protein influences mRNA half-life, cell growth and stress responses, and its own expression is subject to microRNA and deadenylation-dependent control.
