How protein interaction drives apoptosis

"A healthy body depends on the cell division and death that is strictly carried out according to regulations," said Dr Stephanie bleicken, a leading EPR research group in Bochum "When they get out of control, cancer and neurodegenerative diseases will occur." Apoptosis is an important safety mechanism for the body to get rid of damaged, aged or unwanted cells Bcl-2 protein family determines when cell apoptosis begins Some family members induce cell apoptosis by opening mitochondrial membrane pore and releasing apoptosis substrate Other Bcl-2 family members prevent the opening of membrane pores and cell apoptosis Therefore, the interaction of Bcl-2 protein is the key to understand apoptosis In this new study, the researchers used fluorescence correlation spectroscopy to quantify a small Bcl-2 interaction network, including three major components, CBID, Bax and Bcl XL, and studied these protein networks in a roughly cell simulated environment "There are different molecular interactions and innumerable reactions in living cells," said ana Garc í A-S á EZ, a professor at the University of tibingen "In order to understand the components of complex networks, we need to use an initial highly simplified environment, and then continue to add new structures." The researchers in this paper studied in a simulated environment of cytoplasm or mitochondrial membrane The interaction of proteins depends largely on the environment By comparing proteins in the cytoplasmic and membrane environments, the researchers found a contradiction between the results of previous studies The latest research found that the C-terminal helix of bcl XL determines its binding preference Bax can activate spontaneously in the process of self activation under physiological temperature Bas can also recruit BCL XL to the cell membrane The level of formation of Bcl-2 complex was also unraveled: the combination of bcl XL and CBID was stable in both solution (simulated cytoplasm) and membrane However, the binding of bcl XL to Bax only takes place on the membrane, and the affinity is lower than CBID, which results in the reverse transport of Bax It can be concluded that the interaction mode of membrane proteins is different from that of cytoplasm "Because membrane interaction determines the beginning of apoptosis, this is a major discovery," said Garc í A-S á EZ "Bcl-2 protein is responsible for regulating apoptosis, which is closely related to cancer and other diseases Understanding the function of these proteins is a good starting point for the development of new drugs "