Identification of phosphatases that inactivate the endoplasmic reticulum stress sensor Ire1

A self-funded PhD studentship is available in the group of Dr. Martin Schröder in the Department of Biosciences at Durham University to study stress signalling mechanisms originating from the endoplasmic reticulum.

Endoplasmic reticulum (ER) stress contributes to the development and progression of many diverse diseases affecting secretory tissues, such as diabetes and neurodegenerative diseases. The successful candidate will employ modern genetic and molecular techniques to understand the underlying cell biological mechanisms in endoplasmic reticulum stress signalling that maintain the homeostasis of the endoplasmic reticulum.

The bifunctional transmembrane spanning protein kinase-endoribonuclease Ire1 is an evolutionary conserved ER stress sensor. Upon accumulation of unfolded proteins in the ER, Ire1 autophosphorylates and activates its RNase domain. Through processing of mRNAs, such as HAC1 in yeast and XBP1 in mammalian cells, Ire1 remodels the cellular proteome to alleviate ER stress. While activation of Ire1 has been well characterised, much less is known how Ire1 is inactivated once ER stress diminishes.

In this project, you will employ genetic screens in the eukaryotic model organism budding yeast (Saccharomyces cerevisiae) to comprehensively identify phosphatases that are negative regulators of Ire1 and that contribute to the inactivation of Ire1. You will then use a combination of synthetic molecular biology, yeast genetic, and biochemical approaches to characterise how the phosphatases identified in the genetic screen regulate Ire1. To achieve these aims, you will construct novel yeast strains and plasmid vectors for expression of proteins in yeast, characterise the subcellular localisation of fluorescently-tagged Ire1 by confocal microscopy, and use biochemical and electrophoretic techniques to characterise the phosphorylation status of Ire1.

Applicants should possess at least a 2:1 Honours degree, or equivalent, in an appropriate subject (e.g. biochemistry, cell biology, molecular biology, or genetics).

To apply, send a CV including the names of two references and a one page personal statement describing clearly your background, interest and experience in scientific research to martin.schroeder@durham.ac.uk. In your cover letter you should clearly identify the funding source to cover living expenses, tuition fees and bench fees. Further information on this studentship can be obtained by contacting Dr. Martin Schroeder.