Molecular mechanisms of the anaphase-promoting complex and the mitotic checkpoint
The anaphase-promoting complex (APC/C) is a large multi-subunit complex (~1.2 MDa) that functions to regulate cell cycle transitions, specifically the metaphase to anaphase transition in mitosis (when duplicated sister chromatid pairs are separated), the exit from mitosis and maintenance of G1. The APC/C regulates these processes by targeting specific cell cycle proteins (for example cyclins and securin) for proteolysis by the ubiquitin-proteosome system (UPS). The role of the APC/C is to recognise substrates through degrons (D box and KEN box) and assemble a poly-ubiquitin chain of defined linkage onto its substrates. The poly-ubiquitin chain functions as a signal for recognition by the proteasome.
The APC/C is regulated by the mitotic checkpoint that ensures that chromosome segregation is coordinated with the correct attachment of chromosomes to the mitotic spindle. Failure of the mitotic checkpoint causes chromosome mis-segregation and aneuploidy. Other regulatory mechanisms, including activation by co-activator subunits and protein phosphorylation, also determine APC/C activity and substrate specificity.
Atomic model of the anaphase-promoting complex/cyclosome (APC/C) determined using cryo-EM.
The aims of our research are to understand the molecular mechanisms underlying the assembly of this large complex, its capacity to recognize and ubiquitinate proteins in a cell cycle-coordinated manner, and the structural basis for its control by the spindle assembly checkpoint.
To pursue these aims we use a combination of protein crystallography and single particle cryo-electron microscopy of defined reconstituted complexes.
- Alfieri, C., Chang, L., Zhang, Z., Yang, Y., Maslen, S., Skehel, M. and Barford, D. (2016)
Molecular basis of APC/C regulation by the spindle assembly checkpoint.
Nature 536: 431-436
- Zhang, S., Chang, L., Alfieri, C., Zhang, Z., Yang, J., Maslen, S., Skehel, M. and Barford, D. (2016)
Molecular mechanism of APC/C activation by mitotic phosphorylation
Nature 533: 260-264
- Chang, L., Zhang, Z., Yang, J., McLaughlin, S.H. and Barford, D. (2015)
Atomic structure of the APC/C and its mechanism of protein ubiquitination
Nature 522: 450-454
- Chang, L., Zhang, Z., Yang, J., McLaughlin, S.H. and Barford, D. (2014)
Molecular architecture and mechanism of the anaphase-promoting complex
Nature 513: 388-393
- Manolaridis, I., Kulkarni, K., Dodd, R. B., Ogasawara, S., Zhang, Z., Bineva, G., O'Reilly, N., Hanrahan, S. J., Thompson, A. J., Cronin, N., Iwata, S. and Barford, D. (2013)
Mechanism of prenylated CAAX protein processing by the integral membrane protease Rce1
Nature 504: 301-305
- Chao, W.C., Kulkarni, K., Zhang, Z., Kong, E.H., and Barford, D. (2012)
Structure of the mitotic checkpoint complex
Nature 484: 208-213
- Claudio Alfieri
- Elyse Fischer
- Kyle Muir
- Jianguo Shi
- Thomas Tischer
- Ester Vázquez Fernández
- Tobias Wauer
- Kaige Yan
- Jing Yang
- Stanislau Yatskevich
- Ziguo Zhang
- Suyang Zhang