Proteasome function and protein biosynthesis

Purpose of review Protein synthesis and degredation govern protein turnover, which underlies the adaption of organisms to changing developmental, phsiological and environmental needs. The cellular mechanisms of these processes have been increasingly uncovered. Recent findings establishing additional links between protein synthesis and degredation are the topic of this review. Recent findings Several major developments in the field have taken place recently. First, the role of lysosomal-autophagosomal degredation, the established amino acid supplier for protein synthesis, has been demonstrated for additional diverse aspects of cellular physiology. Second, cytosolic protein degredation initiated by the proteasome has been assigned a critical role in sustaining ongoing protein synthesis upon acute nutrient restriction. A number of regulatory possibilities to modulate the intracellular amino acid flux by means of proteasomal degredation are discussed. Finally, the field of translation factor regulation by their degredation has emerged recently and is described here. Summary The elucidation of mechanisms determining protein turnover and, thus, cellular adaptation will help us to understand the (patho)physiological conditions caused or accompanying acute and chronic nutrient deficiencies and should lead to new therapeutic strategies to handle them.