Neddylated Pcu3p accumulates in csn mutants. (a) The indicated csn genes were disrupted in a pcu3-13myc background. Cell lysates of these strains were probed with antibodies against Myc and Pcu1p to reveal neddylated and unmodified forms. (b) GST-Ned8p was overexpressed in csn1 mutants, and modified Pcu3p was detected by immunoblotting with Myc antibodies. The star denotes an unidentified cross-reactive band. (c) Morphology of csn mutants. The indicated strains were fixed in formaldehyde, mounted on microscope slides, and photographed. The elongation phenotype of csn1 mutants is not apparent in other csn mutants. (d) DNA content of csn mutants. The indicated strains were grown to mid log phase, fixed in ethanol, and analyzed by flow cytometry. Note that the broadening of the 2C peak indicative of the described slow S phase progression of csn1 mutants  is completely absent from other csn mutants.