Many proteins have since been unearthed that contain a place with hydrophobic and charged amino acids equally spread as within the peptide of Bak. Ergo, in primary, all BH3 containing proteins can interact, in one way or another, with the hydrophobic groove of Bcl 2 like survival facets. But, this may maybe not be the case under physiological conditions. Firstly, BH3 domains aren’t readily available for binding Ubiquitin conjugation inhibitor in all proteins at all times. BH3 only and Bax like death facets appear to expose their BH3 domain after a post translational modification and/or conformational change. In comparison, Bcl 2 like meats keep this area as integral part of their hydrophobic pocket and are not capable of making it designed for binding to other hydrophobic pockets of Bcl 2 family members. This explains why Bcl 2 and Bcl xL can’t di or oligomerize but quickly Bax and bind BH3 just like proteins to their hydrophobic pockets. Subsequently, the relationships between a particular BH3 containing protein and a Bcl 2 like emergency issue are restricted by intracellular compartimentalization or weak binding affinities. For instance, the peptide of Bax has an almost 100-fold lesser affinity for Bcl xL compared to the peptide of Bak. Thirdly, availability and binding of the peptide towards the hydrophobic pocket of a certain Bcl 2 like success issue may be also regulated by cellular proteins which are not present under in vitro binding conditions. But even if we ought to know the uniqueness of all these interactions, we are still left with the issue of whether sequestering BH3 containing proteins will be the major or even only way by which Bcl 2 like survival elements protect cells from apoptosis. Three studies suggest that the mode of action of Bcl 2 like survival factors is probably more complicated than that. Firstly, various proteins such Kiminas Ras, Raf 1, calcineurin, Bap31, BAG 1/Hsc70, or p53 binding protein p53BP 2 have been identified by yeast two hybrid and interaction cloning practices and shown to connect to Bcl 2 in vitro. None of these proteins contain a BH3 domain, and site directed mutagenesis unveiled that they bind to both the hydrophobic MAPK family groove or the domain of Bcl 2 like survival factors. Unfortunately, binding studies were generally performed with overexpressed proteins, and we do not know whether such interactions certainly occur between endogenous proteins and what the functional consequences of such interactions could be. Bcl 2 and Bcl xL have both been found to control the cell cycle by delaying entry into S phase. This seems to be a separate function from the regulation of cell survival and requires specific amino acid residues within the BH4 domain of those proteins. It’s hence likely that lots of the BH3 lacking binding partners control the cell cycle as opposed to the survival function of Bcl 2 like proteins.