LEI/L-DNase II: interplay between caspase-dependent and independent pathways.

Caspase activation has been seen, for several years, as the biochemical marker of apoptosis. However, in 2005 the Nomenclature Committee on Cell Death (NCCD) established that the 'official' classification of cell death had to rely on morphological criteria owing to the absence of a clear-cut equivalence between structural alterations and biochemical pathways. Actually, the controlled destruction of the cell is coordinated by a proteolytic system involving caspases but also other proteases like cathepsins, calpains and serine proteases. These enzymes participate in an activation cascade that culminates in cleavage of a set of proteins resulting in disassembly of the cell. This disassembling also includes the activation of endonucleases that will destroy a potentially harmful DNA. A caspase-activated DNase performs DNA degradation in caspase-dependent apoptosis, but other endonucleases like L-DNase II or GAAD are activated in caspase-independent apoptosis, allowing the complete dismantling of the cell.