Table 2.
Screening WD40-repeat proteins for CCT interaction. Fifteen yeast proteins predicted to contain 7-blade WD40 repeats, by 3DPSSM structure-based sequence alignment [44], and CDC4, an 8-bladed WD40 [36], non-CCT interacting protein functional in cct1-2 mutant cells at 37°C [28] were analysed for interaction with CCT (column 3) and GroEL (column 4) by quantitative in vitro translation and native gel analysis. The extent of binding to CCT or GroEL was determined by calculating the fraction bound to chaperonin compared to total protein synthesized (weak ≤ 5%, medium = 5–15%, strong ≥ 15%). Results from independent studies are shown in column 5 and referenced in column 6. nd, not done; nt, not previously studied.
| protein | protein complex/function | CCT binding this study | GroEL binding this study | CCT binding published work | ref. |
|---|---|---|---|---|---|
| ASC1 | ribosome subunit/signalling | weak | weak | nt | |
| CAC2 | CAF1-p60/chromatin | medium | yes | nt | |
| CDC4 | Skip1/ubiquitin | weak | yes | no | [28] |
| CDC20 | APC/ubiquitin E3 | strong | yes | yes + in vivo | [32,28] |
| CDC55 | PP2A regB/phosphatase | strong | nd | yes + in vivo | [32,29] |
| CDH1 | APC/ubiquitin E3 | strong | yes | yes + in vivo | [32,28,29] |
| DOA1 | ubiquitin | weak | no | nt | |
| ELP2 | Pol II elongation/transcription | negative | no | nt | |
| HAT2 | histoneAT Type B/acetylation | weak | no | nt | |
| SEC13 | coatomer II/secretion | weak | no | nt | |
| SEC27 | coatomer I/secretion | medium | nd | yes | [32] |
| TAF5 | TFIID/transcription | strong | yes | yes | [32,29] |
| TIF34 | initiation factor 3/translation | negative | no | nt | |
| TUP1 | Tup1-Ssn6/transcription repression | medium | nd | nt | |
| UTP13 | U3 snoRNA (SSU)/translation | medium | yes | nt | |
| VID27 | vacuole/protein degradation | strong | nd | yes | [45,46] |