Proteomic profiling of human induced pluripotent stem cell-derived cardiomyocyte models of modified microtubules

One of the most important microtubule (MT) modification is ¿-tubulin detyrosination (= removal of the C-terminal tyrosine), which is catalysed by vasohibin (VASH1/2) and its chaperone, small vasohibin-binding protein (SVBP). The reverse reaction (= ligation of the C-terminal tyrosine) is catalysed by the tubulin tyrosine ligase (TTL). The role of MT network during progression of cardiac diseases has gained interest in recent years with the findings that MT detyrosination and associated cardiomyocyte stiffness is markedly elevated in hypertrophic cardiomyopathy (HCM) and heart failure. To better understand the role of modified MT in the autophagy-lysososomal process, which is impaired in HCM, we recently generated human induced-pluripotent stem cell (iPSC) lines, deficient in either SVBP or TTL gene with CRISPR/Cas9 genetic tools. The goal of this collaborative project is to define the interactome of the MT-modified iPSC-derived cardiomyocyte lines. The proteomic profiling mass spectrometry programme will be divided in two steps: 1) global proteomic analysis, and 2) targeted interactome after enrichment of proteins, i.e. by co-immunoprecipitation of specific proteins which connect MTs to molecular motors, autophagosome and/or lysosome. In the past years the group of Lucie Carrier successfully implemented disease modeling in iPSC-derived cardiomyocytes in their experimental repertoire and the group of Elke Hammer is well known for long-standing experience in mass spectrometry-based proteomics and data analysis.