The human proto-oncoprotein AF4 interacts with the E3-ligases SIAH1 and SIAH2

The human proto-oncoprotein AF4 was identified to interact with SIAH1 and SIAH2. SIAH proteins belong to the family of ubiquitin E3 ligases that bind to specific target proteins and mediate their destruction via the proteasomal pathway. Therefore, SIAH target proteins are strictly controlled in their specific steady-state level and their turn-over rates. Currently known SIAH target proteins are e.g. DCC, OBF1, TIEG1, Numb, Vav1, NcoR, PML, TCTP and CtIP, which are all degraded by the SIAH system. By contrast, Bag1 and Disabled bind SIAH proteins and block their biological function. We have analyzed which portion…