Postdoctoral Fellow

Salary for this Role:

From £47,500 per annum plus benefits, subject to skills and experience

Job Title:

Reports to:

Closing Date:

Job Description:

Job title: Postdoctoral Fellow - S Boulton lab

Reporting to: Simon J. Boulton, Principal Group Leader

Contract term: This is a full-time, fixed term (4 year) position on Crick terms and conditions of employment.

The Research Group

Our research is focused on understanding the mechanisms that preserve genome stability, with emphasis on DNA double strand break (DSB) repair, the response to replication stress and the maintenance and protection of telomeres. Our work exploits a combination of genetics, functional genomics, proteomics, biochemistry and single molecule biophysics, which has allowed us to discover novel DNA repair genes and provide molecular insights into human diseases, including cancer, and disorders caused by telomere or replisome dysfunction. Most notably, our work has played an instrumental role in shaping our understanding of the regulation and execution of homologous recombination (HR), a key DSB repair pathway frequently inactivated in cancer, how the ends of chromosomes (telomeres) are protected from mis-repair, and more recently how cells sense and tolerate replication stress. This post is funded by a Wellcome Discovery Award to investigate the function and regulation of SLFN11 in replication stress tolerance, cancer development and therapy resistance.

Project summary

The tRNA nuclease SLFN11 is epigenetically silenced in approximately half of all treatment-naive tumours and is the single strongest predictor of resistance to DNA damaging chemotherapy. In response to replication stress, SLFN11 is activated and cleaves type II Leu-tRNAs, triggering translation shutdown and p53-independent apoptosis. Because this silencing is already present before treatment, chemoresistance cannot be the selective pressure that drives it, and why SLFN11 is lost so frequently during tumour evolution is unknown. We have recently implicated SLFN11 in sensing telomeric single-stranded DNA and eliminating ATRX-deficient cells during telomere crisis, such that loss of SLFN11 permits the emergence of survivors that establish alternative lengthening of telomeres (Segura-Bayona et al.). Analysis of DepMap data further associates SLFN11 loss with MYC over-expression and with damaging mutations in ARID1A, SMARCA4 and MSH6. These observations lead to the hypothesis, as yet untested, that SLFN11 loss is selected early in tumour evolution as a means of tolerating endogenous replication stress generated by oncogene activation and other transforming events.

The aim of this project is to test that hypothesis directly in primary human cells. The post holder will use primary cells with a finite replicative lifespan and remain contact-inhibited to ask whether oncogenic (Myc, Ras) and mutational events (p53, Rb, PP2A) select for the loss of SLFN11. The work will involve engineering cells with the aforementioned oncogenic drivers and mutations, and then determining whether these alterations towards cellular transformation activate SLFN11 using the lab's GFP (TTA codon) reporter of tRNA nuclease activity together with markers of the integrated stress response and apoptosis, and establishing whether replication stress and RPA exhaustion accompany activation. The consequences of SLFN11 loss for mutational processes and genome rearrangement will be assessed by whole-genome sequencing in collaboration with Serena Nik-Zainal (Cambridge), with access to the Crick Advanced Sequencing, Bioinformatics and High Throughput Screening STPs.

In this project, some of the specific aims could include but not be limited to:

• Engineering and characterising primary cells models of oncogenic activating and tumour suppressor mutations.
• Determining whether these transforming events activate SLFN11 and whether this is accompanied by replication stress and RPA exhaustion
• Testing whether these events selective for loss of SLFN11 during cellular transformation
• Defining the consequences of SLFN11 loss for transformation, replication dynamics and mutational processes.

Postdoctoral Fellows are expected to lead their own projects, contribute to other projects on a collaborative basis (both in the lab and with external collaborators) and guide PhD students in their research. The ability to work in a team is essential.

Key experience and competencies

The post holder should embody and demonstrate our core Crick values: bold, open, collegial, in addition to the following:

Essential

• PhD in molecular/cell biology, cancer biology, genome stability or a related discipline, or in the final stages of PhD submission
• Prior knowledge and experience in the study of genome stability, the DNA damage response, replication stress and/or oncogene-induced transformation
• Technical expertise in primary mammalian cell culture and models of cellular transformation.
• Experience of quantitative, image-based assays (immunofluorescence, confocal and/or high-content microscopy), live-cell imaging and flow cytometry
• Track record of writing papers as evidenced by publications or submitted manuscripts in referred journals
• Evidence of data presentation at scientific meetings
• Experience of experimental design, including the planning and execution of long-term experiments
• Ability to work independently and also capable of interacting within a group

Desirable

• Experience of long-term culture, senescence, clonal evolution or cellular transformation assays
• Experience of epigenetic analysis, including DNA methylation at silenced loci
• Familiarity with the analysis of whole-genome sequencing data and mutational signatures, or with scripting in R or Python
• Experience of cells biology or of assays for replication dynamics

About Us

At the Crick, we conduct research at the forefront of biomedical research. We combine rigour with an open and collaborative culture, and are outward-looking, reflecting our status as a partnership of six organisations aiming to pool knowledge, ideas and resources.

We have a wide research portfolio with no divisions or departments, bringing biomedical researchers together with clinicians, physical scientists and applied scientists from our pharmaceutical partners.

We aim to attract the most talented researchers and support them to tackle innovative research questions. Our science technology platforms provide our researchers with access to state-of-the-art technology and expertise.

We provide an excellent learning environment with dedicated education programmes in public engagement with science, education and personal development, and a postdoc training programme that prepares scientists for leadership roles in science.

Equality, Diversity & Inclusion

We welcome applications from all backgrounds. We are committed to providing equal employment opportunities, regardless of ethnicity, nationality, gender, sexual orientation, gender identity, religion, pregnancy, age, disability, or civil partnership, marital or family status. We particularly welcome applications from people who are Minority Ethnic as they are currently underrepresented in the Crick at this level.

Diversity is essential to excellence in scientific endeavour. It increases breadth and perspective, leading to more innovation and creativity. We want the Crick to be a place where everyone feels valued and where diversity is celebrated and seen as part of the foundation for our Institute’s success.

The Crick is committed to creating equality of opportunity and promoting diversity and inclusivity. We all share in the responsibility to actively promote dignity, respect, inclusivity and equal treatment and it is our aim to ensure that these principles are reflected and implemented in all strategies, policies and practices.

Read more on our website: https://www.crick.ac.uk/careers-and-study/life-at-the-crick/equality-diversity-and-inclusion