COMMD1 regulates cell proliferation and cell cycle progression by modulating p21 Cip1 levels

Copper metabolism MURR1 domain-containing 1 (COMMD1) is a protein that participates in multiple cellular processes, including copper homeostasis and nuclear factor kappa B (NF-κB) and hypoxia-inducible factor 1α (HIF-1α) signaling. The COMMD1 upstream regulators X-linked inhibitor of apoptosis protein (XIAP) and p300 and downstream targets such as NF-κB and HIF-1α are involved in the regulation of cell proliferation and cell cycle progression. However, whether COMMD1 regulates cell proliferation and the cell cycle remains unclear. In the present study, we demonstrated that both overexpression and knockdown of COMMD1 affected the proliferation of HEK293 cells, and the cell cycle assay revealed that ectopic expression of COMMD1 arrested the cell cycle at the G1 phase. Furthermore, western blot analysis showed that COMMD1 affected p21 Cip1 levels. Taken together, these results suggest that COMMD1 regulates cell proliferation and cell cycle progression by modulating p21 Cip1 levels. Abbreviations COMMD1: Copper metabolism MURR1 domain containing 1; XIAP: X chromosome-linked inhibitor of apoptosis protein; FCS: Fetal calf serum; WCE: Whole cell extracts; RT-PCR: Reverse transcription-polymerase chain reaction; HEK293: Human embryonic kidney 293; ShRNA: Short hairpin RNA; NF-κB: Nuclear factor kappa-light-chain-enhancer of activated B cells; ARF: Alternate reading frame protein product of the CDKN2A locus. COMMD1 was identified to regulate cell proliferation and cell cycle by modulating p21 Cip1 levels through COMMD1 overexpression or knockdown assays.