Brewer Joseph W, Jackowski Suzanne
Department of Microbiology and Immunology, College of Medicine, University of South Alabama, Mobile, AL 36688, USA.
Biochem Res Int. 2012;2012:738471. doi: 10.1155/2012/738471. Epub 2011 Nov 1.
The unfolded protein response (UPR) can coordinate the regulation of gene transcription and protein translation to balance the load of client proteins with the protein folding and degradative capacities of the ER. Increasing evidence also implicates the UPR in the regulation of lipid synthesis and membrane biogenesis. The differentiation of B lymphocytes into antibody-secreting cells is marked by significant expansion of the ER, the site for antibody synthesis and assembly. In activated B cells, the demand for membrane protein and lipid components leads to activation of the UPR transcriptional activator XBP1(S) which, in turn, initiates a cascade of biochemical events that enhance supplies of phospholipid precursors and build machinery for the synthesis, maturation, and transport of secretory proteins. The alterations in lipid metabolism that occur during this developmental transition and the impact of membrane phospholipid restriction on B cell secretory characteristics are discussed in this paper.
未折叠蛋白反应（UPR）可协调基因转录和蛋白质翻译的调控，以平衡客户蛋白负载与内质网（ER）的蛋白质折叠及降解能力。越来越多的证据还表明，UPR参与脂质合成和膜生物发生的调控。B淋巴细胞分化为抗体分泌细胞的过程以ER的显著扩张为特征，ER是抗体合成和组装的场所。在活化的B细胞中，对膜蛋白和脂质成分的需求导致UPR转录激活因子XBP1(S)的激活，进而引发一系列生化事件，增强磷脂前体的供应，并构建分泌蛋白合成、成熟和运输的机制。本文讨论了这一发育转变过程中发生的脂质代谢变化以及膜磷脂限制对B细胞分泌特性的影响。
