CENTROLOC · Genome-wide screen for new centrosome position regulators

Centrosomes are the main microtubule-organizing centers in animal cells and their structure and function are extremely well conserved across evolution. Centrosome localization is a dynamic, cell cycle, and cell type regulated process that plays many critical roles in a variety of cell functions and animal development. I have recently published, as part of my work in the lab of Pierre Gönczy, a siRNA genome wide screen that has successfully identified new regulators of centriole duplication. In this work we have used a HeLa cell line stably expressing the centriolar protein Centrin-1 tagged to GFP. We have developed an algorithm to automatically identify GFP positive foci and use it to measure among other features centriole number. Remarkably, there is information that was extracted from the collection of images that remain to be analyzed and that can reveal new features about centrosome biology. One exciting example is the analysis of centriole position within the cell. I aim to use the data to identify new candidates required for proper centrosome localization in a genome-wide scale. The more straightforward way to achieve this goal will be to identify those conditions where centrosome position is not in close proximity to the nucleus. As a proof of principle I have searched in our database for genes previously reported in literature to influence centrosome-nucleus connection. Preliminary visual inspection showed examples where the percentage of cells displaying an increased nucleus-centriole distance was significantly higher than in control conditions (i.e. BICD2, CENP-F, DCTN1, Nesprin-3 and SUN-1). This preliminary data encourage me to embark on a more systematic and quantitative search of candidates in a genome-wide scale. In order to perform this project I will relocate to a more experience lab in the field of organelle positioning and centrosome-organelle interaction as it is the case of Dr. Rosa M. Rios laboratory located in a leading research institution.