Table 1

Conservation of key regulators of programmed cell death between species

C. elegans

Drosophila

Mammals


Bcl-2 family

2

2

19

CED-4/Apaf-1

1

1

1*

Caspases

4

8

14

BIR proteins

2

4

7

Reaper, Hid and Grim

-

1 each

-

P53

-

1

1


Homologs of most key regulators are found in C. elegans, Drosophila, and mammals; the table shows the number in each class. BIR proteins contain at least one BIR domain and not all of them function as inhibitors of apoptosis (IAPs). Functional homologs that share little or no sequence homology may exist for the other members of the programmed cell death pathway. *In addition to Apaf-1, two other mammalian proteins, Flash and Nod1/Card4 share have similarity to CED-4, but these have not been extensively characterized in vivo (reviewed in [14]).

Tittel and Steller Genome Biology 2000 1:reviews0003.1-reviews0003.6   doi:10.1186/gb-2000-1-3-reviews0003