Extremely Long-Lived Nuclear Pore Proteins in the Rat Brain

摘要

Functional deterioration and accumulation of damage to the proteome is largely re paired through protein turnover where po tentially impaired polypeptides are replaced with new, functional copies. These turnover mechanisms are particularly important in postmitoric cells such as neurons, because they cannot dilute potential ly toxic species through cell division. Nearly all proteins within the human proteome are recycled in less than a few days (1, 2). However, a few extremely long-lived proteins (ELLPs) with half lives on the order of months have been identified (3, 4), including myelin basic protein (MBP). A subset of nuclear pore complex (NPC) proteins, which form transport channels responsible for me diating nuclear trafficking (5), are present but no longer expressed in differentiated cells (6).