Kinases in the early secretory pathway

The scientific progress of the last three decades has largely advanced our knowledge about and understanding of the secretory pathway. Nevertheless, we do not yet completely understand organization and regulation of secretory organelles. The current challenge in the emerging era of systems biology is to identify all key molecules that control different steps in of protein secretion and to integrate their function to understand structure, function and dynamics of the secretory pathway. Inspired by this the proposal will focus on the role of kinases in regulating the early secretory pathway, particularly on the ERGIC. The main aims of the project are: (i) Identify protein kinases involved in transport to and from the ERGIC. (ii) Determine their targets and the role on trafficking in the early secretory pathway (iii) Investigate the effect that changes of traffic load has on their activity. We will use high throughput genome-wide RNAi-mediated knock-down of all known and predicted human kinases. For this we will use an established siRNA library, which has previously been used by the group of Dr. Zerial (MPI, Dresden). The screen will combine automated cell handling and automated image analysis. The results of the screen will be validated and re-examined. Afterwards the role of the kinases in regulating ER-to-Golgi trafficking will be determined using VSVG-tsO45 and a mutant version of ERGIC-53 (that lacks the terminal di- lysine motif) as model cargoes. We will also try to identify targets of the kinases thatturn out to be involved. Finally, the effect of changes in traffic load will be determined on the activity of these kinases. We hope that the results of the project will advance our understanding of homeostasis of the early secretory pathway and its regulation by protein kinases. Given that a multitude of hereditary diseases are associated with defects in the early secretory pathway (e.g. cystic fibrosis, diabetes insipidus, combined factor 5 and factor 8 deficiency, Alzheimers disease, Cranio-lenticulo-sutural dysplasia, alpha1-antitrypsin deficiency, etc) these insights will hopefully provide the basis of novel therapeutic interventions.