How do Rel/NF-B transcription factors regulate apoptosis?
There are three general models by which Rel/NF-B transcription factors may regulate apoptosis: (1) by the direct regulation of genes that inhibit or promote apoptosis; (2) by the regulation of the cell cycle, which then desensitizes or sensitizes a cell to apoptotic signals; and (3) by interaction with cellular proteins whose levels affect the life balance of the cell. Target genes involved in the protective effect of NF-B The mechanism by which NF-B promotes cell survival is almost certainly due, in part, to the upregulation of anti-apoptotic genes, a number of which have recently been identified (Table 3). The general strategy for claiming that an NF-B target gene is involved in cell survival is to show that the gene is directly activated by NF-B under apoptosis-inducing conditions, that inhibition of the gene (e.g., by antisense treatment) abrogates its protective effect, and that ectopic expression of the gene can protect the cell from the apoptotic signal. The Bcl-2 family of prot
