UBC gene transcription is induced during stress and provides extra ubiquitin necessary to remove damaged/unfolded proteins.

[10][14] Polyubiquitin-C has important role in diverse biological processes, such as innate immunity, DNA repair and kinase activity.

[15][16][17] Unanchored polyubiquitin-C are also key signaling molecules that connect and coordinate the proteasome and autophagy to eliminate toxic protein aggregates.

[18] Loss of a single UBC allele has no apparent phenotype, while homozygous deletion of UBC gene leads to mid-gestation embryonic lethality due to a defect in fetal liver development, as well as a delay in cell-cycle progression and increased susceptibility to cellular stress.

[10] It is also reported that homozygous deletion of UBC gene in mouse embryonic fibroblasts will cause decreased cellular Ub level and reduced viability under oxidative stress.