Retrograde traffic modulates contact site formation at the ER and the Golgi (P20*)

• Subject Area: Cell Biology
• Term: Funded in 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 264061860

Vesicular transport is an efficient means by which lipids and proteins are distributed along the endomembrane system or eventually secreted from cells. Within the secretory pathway, the COPI vesicle coat operates to ensure retrograde transport from the Golgi apparatus to the endoplasmic reticulum (ER). Recognized functions of retrograde transport are the recycling of lipids and forward-transport protein machinery as well as the retrieval of escaped ER-resident proteins. Here, we propose a novel function of retrograde traffic in the distribution of contact-site proteins along the early secretory pathway. This hypothesis predicts that the respective extent of contact site formation at the ER and the trans-Golgi network (TGN) is regulated by the activity of COPI-dependent vesicular traffic. Along those lines, we have recently discovered that several contact site proteins interact with COPI. In this proposal, we will map their COPI recognition motifs and the respective recognition domains on COPI. We will test whether the regulation of their recognition by COPI affects the relative distribution of different contact sites or their functionality.

• DFG Programme: Collaborative Research Centres
• Subproject of: SFB 1190: Compartmental Gates and Contact Sites in Cells
• Applicant Institution: Georg-August-Universität Göttingen
• Project Head: Professorin Dr. Blanche Schwappach-Pignataro