title: BAG-1 inhibits p53-induced but not apoptin-induced apoptosis.
abstract: BAG-1 has been identified as a Bcl-2-binding protein that inhibits apoptosis, either alone or in co-operation with Bcl-2. Here we show that BAG-1 inhibits p53- induced apoptosis in the human tumour cell line Saos-2. In contrast, BAG-1 was unable to inhibit the p53-independent pathway induced by apoptin, an apoptosis-inducing protein derived from chicken anaemia virus. Whereas BAG-1 seemed to co-operate with Bcl-2 to repress p53-induced apoptosis, co-expression of these proteins had no inhibitory effect on apoptin-induced apoptosis. Moreover, Bcl-2, and to some extent also BAG-1, paradoxically enhanced the apoptotic activity of apoptin. These results demonstrate that p53 and apoptin induce apoptosis through independent pathways, which are differentially regulated by BAG-1 and Bcl-2.
authors.affiliation: Laboratory for Molecular Carcinogenesis, Leiden University, The Netherlands.
authors.forename: A A
authors.initials: AA
authors.lastname: Danen-van Oorschot
authors.forename: A I
authors.initials: AI
authors.lastname: den Hollander
authors.forename: S
authors.initials: S
authors.lastname: Takayama
authors.forename: J C
authors.initials: JC
authors.lastname: Reed
authors.forename: A J
authors.initials: AJ
authors.lastname: van der Eb
authors.forename: M H
authors.initials: MH
authors.lastname: Noteborn