DAP-5 is involved in MycN/IFN gamma-induced apoptosis in human neuroblastoma cells

Death associated protein-5 (DAP-5) is a ubiquitously expressed member of th e translation initiation factor eIF4G family that lacks the eIF4E binding s ite, A dominant negative fragment of DAP-5 protects HeLa cells from IFN gam ma -induced cell death. By employing a functional approach we examined the role of DAP-5 in human neuroblastoma cells that are sensitized for IFN gamm a -induced apoptosis by tetracycline controlled MYCN expression. DAP-5 frag ment transcribed at high levels and translated into a functional miniprotei n of 28 kDa protected neuroblastoma cells from IFN gamma -induced apoptosis . Reduced serum levels were toxic to cells constitutively expressing DAP-5 fragment suggesting that DAP-5 protein is essential for both viability and death of human neuroblastoma cells. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.