In Caulobacter crescentus, the degree of assembly of adaptors dictates which substrates are degraded. Substrate 1 is degraded by an active ClpXP following binding of a dephosphorylated CpdR adaptor, which primes ClpXP for selective substrate recognition. Substrate 2 is bound by the RcdA adaptor, which delivers cargos to a CpdR-activated protease and restricts degradation of substrate 1. Finally, the PopA adaptor can bind RcdA to form a complex that delivers Substrate 3. The hierarchical assembly of these adaptors during the Caulobacter cell cycle leads to ordered, progressive degradation of key regulators.