Component of the regulatory network controlling carbon source utilization through ubiquitination and deubiquitination involving creA, creB, creC, creD and acrB. Required to prevent the proteolysis of the CreB deubiquitinating enzyme in the absence of carbon catabolite repression. CreB deubiquitinating enzyme stabilized in a complex with the CreC leads to the expression of genes such as those in the proline and quinate pathways. Interacts with creB. Belongs to the WD repeat creC family.