Charakterisierung eines neuen Sortierungsweges für ein Protein der Plasmamembran

• Applicant: Privatdozent Dr. Matthias Seedorf
• Subject Area: Cell Biology
• Term: from 2004 to 2008
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5443209

Eukaryotic cells mainly use the secretory (sec)-pathway for the biogenesis of plasma membrane (PM) proteins. This transport route begins with the insertion of membrane proteins into the membrane of the endoplasmic reticulum (ER), followed by the vesicular transport of cargo to the Golgi-apparatus and the sorting to the final destination. Recent studies have suggested that some secreted and membrane proteins are sorted independently of the sec-pathway. The molecular mechanisms underlying these processes are unknown. In the yeast Saccharomyces cerevisiae, the polytopic membrane protein Ist2p is encoded by a localized mRNA that has been found in proximity of the ER at the periphery of daughter cells. We have shown hat the delivery of Ist2p to the PM is independent of sec-mediated ER to Golgi-, intra-Golgi and Golgi to PM-transport suggesting that Ist2p travels on a novel trafficking pathway to the PM. The properties of proteins that define them as cargo for this novel Ich denkepathway and the factors that mediate their trafficking are unknown. Therefore we aim to characterize the sorting signals of Ist2p, which mediate the sec-independent transport to the PM, and we are going to identify the involved factors by employing yeast genetics.

• DFG Programme: Research Grants