BIRD-2, a peptide that specifically disrupts the Bcl2/IP3R complex, was utilized to further verify the mitochondrial Ca2+ regulatory mechanism via the Bmal1-Bcl2/IP3R signaling pathway. It was found that BIRD-2 aggravated mitochondrial Ca2+ overload and apoptosis in vitro.
The anti-apoptotic factor Bcl-2 is over-expressed in B-cell lymphoma cells as their main survival mechanism by binding to IP3R2 on endoplasmic reticulum (ER). In this study, a cell-penetrating version of BIRD-2 peptide (Bcl-2/IP3R Disrupter-2 peptide with a TAT sequence) made by LifeTein was used to break up the complex formed by Bcl-2 and IP3R2 in human diffuse large B-cell lymphoma (DLBCL) cells. Ca2+ signaling-related events are suggested to be the killing mechanism of BIRD-2 peptide on DLBCL cells.