Imperial College London
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ProfessorChristianSpeck

Faculty of Medicine, Institute of Clinical Sciences

Professor of Genome Biochemistry & Molecular Biology
 
 
 
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Contact

 

+44 (0)7961 815 557chris.speck Website CV

 
 
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Location

 

2.14BLMS BuildingHammersmith Campus

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Summary

 

Publications

Citation

BibTex format

@article{Herrera:2015:nar/gkv881,
author = {Herrera, MC and Tognetti, S and Riera, A and Zech, J and Clarke, P and Fernandez-Cid, A and Speck, C},
doi = {nar/gkv881},
journal = {Nucleic Acids Research},
pages = {10238--10250},
title = {A reconstituted system reveals how activating and inhibitory interactions control DDK dependent assembly of the eukaryotic replicative helicase},
url = {http://dx.doi.org/10.1093/nar/gkv881},
volume = {43},
year = {2015}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - During G1-phase of the cell-cycle the replicative MCM2-7 helicase becomes loaded onto DNA into prereplicativecomplexes (pre-RCs), resulting in MCM2-7 double-hexamers on DNA. In S-phase, Dbf4-dependent kinase (DDK) and cyclin-dependent-kinase (CDK) direct with the help of a large number ofhelicase-activation factors the assembly of a Cdc45-MCM2-7-GINS (CMG) complex. However, in theabsence of S-phase kinases complex assembly is inhibited, which is unexpected, as the MCM2-7double-hexamer represents a very large interaction surface. Currently it is unclear what mechanismsrestricts complex assembly and how DDK can overcome this inhibition to promote CMG-assembly. Wedeveloped an advanced reconstituted-system to study helicase activation in-solution and discoveredthat individual factors like Sld3 and Sld2 can bind directly to the pre-RC, while Cdc45 cannot. WhenSld3 and Sld2 were incubated together with the pre-RC, we observed that competitive interactionsrestrict complex assembly. DDK stabilizes the Sld3/Sld2-pre-RC complex, but the complex is only shortlived,indicating an anti-cooperative mechanism. Yet, a Sld3/Cdc45-pre-RC can form in the presenceof DDK and the addition of Sld2 enhances complex stability. Our results indicate that helicaseactivation is regulated by competitive and cooperative interactions, which restrict illegitimate complexformation and direct limiting helicase-activation factors into pre-initiation complexes.
AU  - Herrera,MC
AU  - Tognetti,S
AU  - Riera,A
AU  - Zech,J
AU  - Clarke,P
AU  - Fernandez-Cid,A
AU  - Speck,C
DO  - nar/gkv881
EP  - 10250
PY  - 2015///
SN  - 1362-4962
SP  - 10238
TI  - A reconstituted system reveals how activating and inhibitory interactions control DDK dependent assembly of the eukaryotic replicative helicase
T2  - Nucleic Acids Research
UR  - http://dx.doi.org/10.1093/nar/gkv881
UR  - http://hdl.handle.net/10044/1/25983
VL  - 43
ER  -
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