Mapping nuclear pore surface with atomic force microscopy

• Applicant: Professor Dr. Hans Oberleithner
• Subject Area: Anatomy and Physiology
• Term: from 2006 to 2009
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 16524566

Nuclear pore complexes (NPCs) are supramolecular assemblies of proteins that span the nuclear envelope of eukaryotic cells. Transport of ions and macromolecules occurs through this pathway. It is still unclear whether different routes exist for different cargos and whether the access to such routes depends on the hydrophobic properties of the NPC surface. This open question is addressed by NPC surface mapping using atomic force microscopy (AFM). Surface scans across individual NPCs will be performed with narrow line spacing using AFM tips with different hydrophobic or hydrophilic properties. Derived from the AFM tip interaction with the NPC surface (i.e. adhesion forces) the hypothesis is tested whether the NPC surface consists of zones that separate transport routes into one for inorganic ions (hydrophilic route), one for small organic macromolecules (amphiphilic route) and one for large cargo using the central channel (hydrophobic route). A combination of electrical conductance and fluorescent dextran measurements will be used to selectively localize the individual pathways. With high resolution AFM imaging of the NPC surface we will search for the postulated peripheral channels in the NPC periphery. The goal of the project is a better understanding of nuclear translocation processes at the single NPC level.

• DFG Programme: Research Grants
• Major Instrumentation: Raster-Sonden-Mikroskop
• Instrumentation Group: 5091 Rasterkraft-Mikroskope