A microscopic study of cohesin

Rhodes, J

Abstract:: Cohesin is a ring-shaped Smc (Structural Maintenance of Chromosomes) complex that mediates DNA-DNA interactions between chromosomes (sister chromatid cohesion) and within chromosomes (looping). The mechanisms behind loop formation and cohesion establishment are not known despite cohesin's discovery 20 years ago. In this thesis findings are presented from two projects: one examining the establishment of sister chromatid cohesion and the other the formation of DNA loops by cohesin.

Expand abstract
Collapse abstract

Actions

Email

Email this record

Send the bibliographic details of this record to your email address.

Your Email
Please enter the email address that the record information will be sent to.

-
Your message (optional)
Please add any additional information to be included within the email.
Share
Cite

Cite this record

APA Style

Rhodes, J. (2017). A microscopic study of cohesin [PhD thesis]. University of Oxford.

MLA Style

Rhodes, J. A Microscopic Study of Cohesin. 2017. University of Oxford, PhD thesis.

Chicago Style

Rhodes, J. 2017. “A Microscopic Study of Cohesin.” PhD thesis, University of Oxford.
Print

Access Document

Files:: James Rhodes Thesis Mirror.pdf

(Preview, pdf, 8.2MB, Terms of use)

Authors

+ Rhodes, J More by this author

Division:: MSD
Department:: Biochemistry
Role:: Author

Contributors

+ Nasmyth, K

Role:: Supervisor

+ Cancer Research UK More from this funder

Grant:: C573/A12386

+ Wellcome Trust More from this funder

Grant:: 091859/Z/10/Z

+ European Research Council More from this funder

Grant:: 294401

DOI:: 10.5287/ora-gaobjoex4
Type of award:: DPhil
Level of award:: Doctoral
Awarding institution:: University of Oxford

Subjects:: Biochemistry
UUID:: uuid:46b27afd-c3c4-4e7b-9179-99795de54d58
Deposit date:: 2018-02-06
ARK identifier:: ark:/29072/ora_46b27afdc3c44e7b917999795de54d58

Related item:: Cohesin Can Remain Associated with Chromosomes during DNA Replication.
Description:: To ensure disjunction to opposite poles during anaphase, sister chromatids must be held together following DNA replication. This is mediated by cohesin, which is thought to entrap sister DNAs inside a tripartite ring composed of its Smc and kleisin (Scc1) subunits. How such structures are created during S phase is poorly understood, in particular whether they are derived from complexes that had entrapped DNAs prior to replication. To address this, we used selective photobleaching to determine whether cohesin associated with chromatin in G1 persists in situ after replication. We developed a non-fluorescent HaloTag ligand to discriminate the fluorescence recovery signal from labeling of newly synthesized Halo-tagged Scc1 protein (pulse-chase or pcFRAP). In cells where cohesin turnover is inactivated by deletion of WAPL, Scc1 can remain associated with chromatin throughout S phase. These findings suggest that cohesion might be generated by cohesin that is already bound to un-replicated DNA.
Related item:: Scc2/Nipbl hops between chromosomal cohesin rings after loading.
Description:: The cohesin complex mediates DNA-DNA interactions both between (sister chromatid cohesion) and within chromosomes (DNA looping). It has been suggested that intra-chromosome loops are generated by extrusion of DNAs through the lumen of cohesin's ring. Scc2 (Nipbl) stimulates cohesin's ABC-like ATPase and is essential for loading cohesin onto chromosomes. However, it is possible that the stimulation of cohesin's ATPase by Scc2 also has a post-loading function, for example driving loop extrusion. Using fluorescence recovery after photobleaching (FRAP) and single-molecule tracking in human cells, we show that Scc2 binds dynamically to chromatin, principally through an association with cohesin. Scc2's movement within chromatin is consistent with a 'stop-and-go' or 'hopping' motion. We suggest that a low diffusion coefficient, a low stoichiometry relative to cohesin, and a high affinity for chromosomal cohesin enables Scc2 to move rapidly from one chromosomal cohesin complex to another, performing a function distinct from loading.

Terms of use

Copyright holder:: Rhodes, J

Licence:: Terms and Conditions of Use for Oxford University Research Archive

Views and Downloads

About views and downloads

FAIR score

If you are the owner of this record, you can report an update to it here: Report update to this record

Thesis

A microscopic study of cohesin

Actions

Access Document

Authors

Contributors

Terms of use

Views and Downloads

Altmetrics

Dimensions

FAIR score

Thesis

A microscopic study of cohesin

Actions

Access Document

Authors

Contributors

Funding

Bibliographic Details

Item Description

Related Items

Terms of use

Metrics

Views and Downloads

Altmetrics

Dimensions

FAIR score