First published online September 28, 2007
Development 134, 2004e (2007)
© The Company of Biologists Limited
Differing routes to apoptosis by RB
The well-known tumour suppressor functions of Retinoblastoma (RB) protein
are mainly attributed to its cell-cycle blocking activities. But now on
p. 3691, Schertel and
Conradt report that RB and its associated proteins also function by promoting
apoptosis in differing ways. Their studies of lin-35 RB
loss-of-function C. elegans mutants, in which the constitutive germ
cell apoptosis that normally occurs in adult hermaphrodites is decreased, show
that lin-35 promotes germ cell apoptosis by repressing ced-9
- an anti-apoptotic gene and BCL2 orthologue. The genes
dpl-1 DP, efl-1 E2F and efl-2 E2F, which encode
proteins that complex with RB, also promote germ cell apoptosis, but they do
so by inducing the expression of the pro-apoptotic genes ced-4 and
ced-3. Finally, the authors show that lin-35, dpl-1 DP and
efl-2 E2F also promote DNA-damage-induced apoptosis but by
controlling the expression of different target genes and not via ced-9,
ced-4 and ced-3. Together, these important findings provide new
avenues of research for investigating the differing tumour-suppressor
functions of RB, particularly in mammals.
Related articles in Development:
- C. elegans orthologs of components of the RB tumor suppressor complex have distinct pro-apoptotic functions
- Claus Schertel and Barbara Conradt
Development 2007 134: 3691-3701.
[Abstract]
[Full Text]
