Bcl-2/E1B 19kDa-interacting protein 3-like protein (Bnip3L) interacts withBcl-2/Bcl-x(L) and induces apoptosis by altering mitochondrial membrane permeability
T. Imazu et al., Bcl-2/E1B 19kDa-interacting protein 3-like protein (Bnip3L) interacts withBcl-2/Bcl-x(L) and induces apoptosis by altering mitochondrial membrane permeability, ONCOGENE, 18(32), 1999, pp. 4523-4529
We have previously reported on cloning of the human gene encoding Bcl-2/ade
novirus E1B 19 kDa-interacting protein 3-like protein (Bnip3L) and its grow
th inhibitory effect on cancer cells. Here we show that Bnip3L contains a m
otif similar to the BH3 domain which is conserved in Bcl-2 family proteins
as well as containing a membrane-anchoring domain, and that Bnip3L interact
s with Bcl-2 and Bcl-x(L). Immunofluorescence microscopy revealed that Bnip
3L was localized in the mitochondria, when in the presence of the membrane-
anchoring domain. Transient expression of Bnip3L induced apoptosis of Rat-1
and HeLa cells and mutational analysis revealed that the BH3 domain and th
e membrane-anchoring domain were required for Bnip3L to induce cell death.
Addition of recombinant Bnip3L to isolated mitochondria induced membrane po
tential loss and cytochrome c release both of which hale been suggested to
be prerequisite for apoptotic cell death, These results suggest that Bnip3L
is one of the BH3-containing proapoptotic proteins and that it targets the
mitochondria when inducing apoptosis.