Figure 1.

Domain structure of budding yeast CSN proteins and csn deletion phenotype(A) Schematic representation of budding yeast genes encoding proteins identified in a stable complex with Rri1p/Csn5p. Conserved MPN and PCI domains are highlighted as red and blue boxes, respectively. Consistent with the typical localization pointed out in the original report [11], the PCI domains of budding yeast CSN proteins are located in the C-terminus. The table to the right lists the ORF names next to published gene names, and names assigned by Glickman and colleagues (personal communication, denoted by ^*). (B) Summary of published budding yeast CSN protein interactions. Two-hybrid interactions [32,33] are indicated by dotted lines, in vivo protein interactions identified by affinity purification of Rri1p/Csn5p interacting proteins [28] are indicated by solid lines. (C) Effect of deletion of csn genes on Rub1p modification of Cdc53p. The indicated strains were grown in YPD media to an optical density of ~0.8 and total protein lysate was prepared by bead lysis in a buffer containing 20 mM Hepes pH 7.4, 150 mM NaCl, 0.2% Triton X-100, 1 mM EDTA, and 50 mM NaF, 1 mM DTT, 1 mM PMSF, 17 ug/ml aprotinin, 10 ug/ml leupeptin, and 10 ug/ml pepstatin. Lysates were separated on SDS gels and the native and Rub1p-modified forms of Cdc53p were detected by immunoblotting with Cdc53p antibodies (purchased from Santa Cruz Biotechnology, sc-6717). Unmodified and Rub1p-modified Cdc53p are indicated.