The ubiquitin-like proteins SUMO-1 and SUMO-2 are covalently conjugated to a wide range of target proteins where they serve as subunits of complex protein associations (sub-proteomes). These covalent modifications play important roles in cellular processes such as transport, regulation of transcription, signalling, and others. In this proposed project I would like to take advantage of several advanced techniques in molecular cell biology and mass spectrometry.
In the first part of my study I will define the proteins covalently interacting with each of the SUMO paralogues in human cells. To achieve this I will use cell lines with integrated versions of TAP-tagged SUMO-1 and -2, which will allow me to recover them together by affinity with other tightly bound proteins. I will then determine how the abundance of proteins modified by SUMO changes during the course of the cell cycle and in response to stress conditions such as UV, heat and hypoxia.
Quantitative changes in modified proteins will be determined by mass spectrometry using SILAC (Stable Isotope Labelling by Amino acids in Cell culture) technique. These experiments will add significant, new and valuable data concerning SUMO sub-proteomes. Obtained results should allow for creation of complex and hopefully quite clear picture of the relationships among all the analysed proteins.
Summarizing, these data should help our understanding of the many cellular processes not necessarily directly involved in the SUMO sub-proteomes. Lists of SUMO targets will be made available to the scientific community so that groups with an interest in a particular protein can determine the role of SUMO modification in its function.
Call for proposal
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