BCL2L1 Research Reagents

BCL2L1 Background

Because of alternative splicing of BCL2L1 mRNA, the BCL2L1 gene encodes two different protein products: a cytoprotective factor of 233 residues (BCL-XL) and a smaller polypeptide (170 residues) that exerts BCL-XL-antagonizing functions (BCL-XS) ^[1]. Like other BCL-2 proteins, BCL-XL contains four distinct BCL-2 homology (BH) domains (BH1-BH4) as well as a transmembrane region that contributes to its localization to the mitochondrial outer membrane (MOM), the endoplasmic reticulum (ER), and the nuclear envelope ^[1][2][3]. However, BCL-XS lacks both the BH1 and BH2 domains ^[1][4]. BCL-XL is mainly expressed in most physiological conditions ^[5], but BCL-XS often predominates in situations of developmental and pharmacological cell death ^[6][7]. Similar to BCL-2, BCL-XL exerts the anti-apoptotic function or prosurvival role. BCL-XL sequesters its proapoptotic counterparts BAX and BAK in inhibitory interactions, preventing the formation of lethal pores in the mitochondrial outer membrane (MOM), as well as to multiple BH3-only proteins such as BAD, thus blocking apical proapoptotic signals ^[8]. Besides, BCL-XL has been suggested to execute cytoprotective functions by detaining a cytosolic pool of the pro-apoptotic transcription factor p53 ^[9] and by binding to the voltage-dependent anion channel 1 (VDAC1), thereby repressing the mitochondrial permeability transition (MPT) ^[10][11]. In particular, BCL-XL has been shown to regulate multiple pathophysiological processes, including mitochondrial ATP synthesis ^[12], protein acetylation ^[13], autophagy, and mitosis.

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