On the role of the chaperonin CCT in the just-in-time assembly process of APC/C^Cdc20

Abstract 

The just-in-time hypothesis relates to the assembly of large multi-protein complexes and their regulation of activation in the cell. Here I postulate that chaperonins may contribute to the timely assembly and activation of such complexes. For the case of anaphase promoting complex/cyclosome^Cdc20 assembly by the eukaryotic chaperonin chaperonin containing Tcp1 it is shown that just-in-time synthesis and chaperone-assisted folding can synergise to generate a highly regulated assembly process of a protein complex that is vital for cell cycle progression. Once dependency has been established transcriptional regulation and chaperonin-dependency may have co-evolved to safeguard the timely activation of important multi-protein complexes.

Keywords: Chaperonin, CCT, APC/C, Just-in-time-assembly

Abbreviations: APC/C, anaphase promoting complex/cyclosome, CCT, chaperonin containing Tcp1, YMC, yeast metabolic cycle, PP2A, protein phosphatase 2A complex, TFIID, transcription factor II D complex