| Siah 1 interacts with the scaffold protein POSH to promote JNK activation and apoptosis . ^^^ Here , we show that Siah 1 is a binding partner for POSH ( plenty of SH3s ) , a scaffold component of the apoptotic JNK pathway , and that Siah contributes to death of neurons and other cell types by activating the JNK pathway . ^^^ This stabilization requires JNK pathway activation and interaction with POSH and is enhanced by phosphorylation of SIAH 1 at tyrosines 100 and 126 . ^^^ |