| Wild type Ube4b also requires N 16 to bind VCP , despite a more C terminal binding site in invertebrate orthologues . ^^^ We conclude that N terminal sequences of Wld ( S ) protein influence the intranuclear location of both ubiquitin proteasome and NAD ( + ) synthesis machinery and that an evolutionary recent sequence mediates binding of mammalian Ube4b to VCP . . ^^^ |