Glucose deprivation is associated with Chk1 degradation through the ubiquitin-proteasome pathway and effective checkpoint response to replication blocks

► Chk1 protein levels are regulated differently depending on glucose concentrations. ► Chk1 is degraded through the ubiquitin-proteasome pathway upon glucose deprivation. ► The molecular mechanism is distinct from genotoxic stress-induced degradation. ► Glucose deprivation induces defective checkpoint response to replication blocks.