Removal of 'spare' proteins

摘要

Membrane proteins that fail to be delivered to the endoplasmic reticulum must be degraded rapidly to avoid inappropriate aggregation and disruption of protein homeostasis. The mechanism of this process is unknown. Bag6, a chaperone complex involved in protein targeting, has now been identified as part of this mechanism. Bag6 captures mislocalized proteins and couples them to the degradation pathway mediated by ubiquitin. This process could degrade unwanted proteins rapidly without the futile engagement of cytosolic folding machinery.