Bid

Different types of cell death have classically been identified by discrete morphological changes. The hallmarks of apoptosis include cell shrinkage, nuclear fragmentation and membrane blebbing whereas necroptosis is characterized by cell swelling and plasma membrane breakdown. While these two forms of cell death are clearly distinct, substantial crosstalk occurs between them.  Accordingly, it is becoming increasingly important to understand how these processes differ and to understand ways to differentiate them in cellular populations. 

Apoptosis is a method of programmed cell death that is notably characterized by a morphological change in cellular nuclei and membrane appearance.  Not to be confused with necrosis, apoptosis is a pathway that is induced by a variety of factors that activate cysteine proteases known as caspases to lead the cell to its ultimate death versus natural death of a cell.

p53, the protein product of the tp53 gene, is one of the most widely studied tumor suppressor proteins in cancer research.  p53 is unique in that it demonstrates both tumor suppressive and tumor progressive properties depending on whether it is functional or mutated.  The most common mutation in the p53 protein that leads to lack of tumor suppression activity is a missense mutation, however frameshift or nonsense mutations are also common.  In fact, mutant p53 has exhibited dominant negative inhibition of the wild type version of the protein, demonstrating the fact that the p53 pat

Caspase-2 is a highly conserved member of the caspase family involved in the initiation and execution of apoptosis. While its function is still poorly understood, caspase-2 is thought to be important for apoptosis in response to DNA damage, bacterial infection, or abnormal mitosis (1). Caspase-2 contains an N-terminal caspase recruitment domain, the large p19 subunit containing the active site, and the small C-terminal p12 subunit (1). In response to various apoptotic signals caspase-2 undergoes dimerization.

B-cell lymphoma 2 (Bcl-2) protein is an oncogene that normally acts as an apoptotic inhibitor and localizes to the mitochondrial membrane where it prevents the release of cytochrome c. The Bcl-2 protein family consists of over 20 proteins each containing at least one Bcl-2 homology (BH) domains and have either proapoptic or antiapoptotic activities.