Description
Apoptosis is mediated by death domaincontaining adapter molecules and a caspase family of proteases. Certain serine/threonine protein kinases, such as ASK-1 and RIP, are mediators of apoptosis. A novel serine/threonine kinase that mediates apoptosis was recently identified and designated ZIP kinase. ZIP kinase contains an Nterminal kinase domain and a Cterminal leucine zipper structure and binds to ATF4, a member of ATF/CREB family. ZIP kinase has high sequence homology to DAP kinase (deathassociated protein kinase), a mediator of apoptosis induced by gamma interferon. Overexpression of ZIP kinase induces apoptosis. ZIP and DAP kinases represent a novel kinase family which mediates apoptosis through their catalytic activities. Messenger RNA for ZIP kinase is widely expressed in a variety of human tissues