Related Experiment Video
Updated: Sep 20, 2026

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro
Published on: January 11, 2017
Components involved in assembly and dislocation of iron-sulfur clusters on the scaffold protein Isu1p
Ulrich Mühlenhoff1, Jana Gerber, Nadine Richhardt
1Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch Strasse 6, D-35033 Marburg, Germany.
Abstract:
The mitochondrial proteins Isu1p and Isu2p play an essential role in the maturation of cellular iron-sulfur (Fe/S) proteins in eukaryotes. By radiolabelling of yeast cells with 55Fe we demonstrate that Isu1p binds an oxygen-resistant non-chelatable Fe/S cluster providing in vivo evidence for a scaffolding function of Isu1p during Fe/S cluster assembly. Depletion of the cysteine desulfurase Nfs1p, the ferredoxin Yah1p or the yeast frataxin homologue Yfh1p by regulated gene expression causes a strong decrease in the de novo synthesis of Fe/S clusters on Isu1p. In contrast, depletion of the Hsp70 chaperone Ssq1p, its co-chaperone Jac1p or the glutaredoxin Grx5p markedly increased the amount of Fe/S clusters bound to Isu1p, even though these mitochondrial proteins are crucial for maturation of Fe/S proteins. Hence Ssq1p/Jac1p and Grx5p are required in a step after Fe/S cluster synthesis on Isu1p, for instance in dissociation of preassembled Fe/S clusters from Isu1p and/or their insertion into apoproteins. We propose a model that dissects Fe/S cluster biogenesis into two major steps and assigns its central components to one of these two steps.
Related Concept Videos
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Disassembly of Intermediate Filaments
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Protein Complex Assembly
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Coat Assembly and GTPases
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Mechanism of Filopodia Formation
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...

