FIG. 6.

Ctk2p ubiquitin conjugates. W303-1B (wild type) cells cotransformed with plasmid YEp105 (Myc-tagged ubiquitin [Myc-Ub]) and either a control plasmid (−) or the CTK2-HA construct were grown in SD medium to an OD₆₀₀ of 0.8 or 3 as indicated. CuSO₄ was (+) or was not (−) added overnight to the cultures in order to induce expression of the Myc-tagged ubiquitin. After immunoprecipitation with HA polyclonal antibodies, proteins were analyzed by Western immunoblotting with monoclonal Myc (upper panel) and monoclonal HA (lower panel) antibodies successively. Arrows and asterisks indicate bands corresponding to Ctk2p and nonspecific products, respectively.