Abstract

ROLE OF CALCIUM IN THE APOPTOSIS AND INVOLVEMENT OF OTHER KEY PLAYERS

Prajjwal* and Ms. Roshmi Ray

Abstract

Apoptosis, cell death that has been predetermined is a very complex mechanism of cell death that is regulated by several intrinsic and extrinsic factors. Over the past several years an extensive approach has been made on the mechanism of apoptosis and the role of calcium, Bcl-2 proteins, caspases, and several other factors. Calcium within the cell is discovered to be a participant in the functioning of the cell by binding to calcium-sensitive effector proteins or by binding to cytosolic calcium-binding protein (calmodulin). Gene expression, cell proliferation, balance energy supply and demand, and apoptosis, autophagy. Accumulation of calcium and the release of cytochrome c from mitochondria, a major key factor in apoptosis this mechanism shows the involvement of mitochondria in apoptosis. In addition, Bcl-2 family proteins (anti-apoptotic and pro-apoptotic) also play a significant influence in the process's regulation by binding to different types of substrates and cleaving specific intracellular enzymes, receptors. Pro-apoptotic proteins (Bax. Bak, Bid) are always found to be that apoptosis is initiated by this protein. An executioner caspase (-3) participated in the cleaving of IP3R and cytochrome c in inhibition of IP3R calcium regulating activity by binding on it. Mitochondrial activity is mainly seen when the intrinsic pathway is the reason for the initiation of apoptosis while the ligation of death receptors such as Tumor necrosis factor receptor 1 (TNFR1) is the reason for the activation of the extrinsic pathway which resulted in the formation of DISC. Caspase (pro-caspase-8) is activated by the Deathinducing signaling complex (DISC). In this review paper, we tried to summarize all the current knowledge including the cross-talk between the endoplasmic reticulum (ER) and mitochondria, the role of calcium, Bcl-2 proteins involvement, caspase activation, and mitochondrial organelles that are involved as a key player in apoptosis.

Keywords: Apoptosis pathways; Calcium homeostasis; IP3R receptors; Bcl-2 family proteins; Caspase.