The unfolded protein response signaling pathways in molluscs
Keywords:molluscs, unfolded protein response (UPR), signaling pathway, molecular components, expression profile, stress response
Unfolded protein response (UPR) as collective signal transduction pathways is essential for
surviving the endoplasmic reticulum (ER) stress in vertebrates and invertebrates. Upon accumulation of unfolded proteins in the ER lumen, UPR increases the degradative and protein-folding capacities of cells and decreases global protein synthesis to maintain the cell homeostasis. Because of their importance in cellular stress and protein folding process, UPR signaling pathways receive increasing attentions, and their components and multiple regulation functions have been well characterized in mammals, fly, and worm etc. Molluscs are widely distributed in various environments with high species diversity, which exhibit remarkable capacity for adaptation and survival upon diverse stressors. Because of the homeostatic role in response to ER stress, the knowledge about UPR would be helpful for understanding the wide distributions, living habits and adaptability to the environment of molluscs. This review summarizes the UPR signaling pathways in molluscs with the emphasis on recent research progresses about the characteristics of molluscan UPR signaling pathway members and their expression profiles in response to various environmental stressors.