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Updated: Feb 27, 2026

Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
Nucleotide-dependent farnesyl switch orchestrates polymerization and membrane binding of human guanylate-binding
Sergii Shydlovskyi1, Anke Y Zienert2, Semra Ince1
1Physical Chemistry I, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780 Bochum, Germany.
Abstract:
Dynamin-like proteins (DLPs) mediate various membrane fusion and fission processes within the cell, which often require the polymerization of DLPs. An IFN-inducible family of DLPs, the guanylate-binding proteins (GBPs), is involved in antimicrobial and antiviral responses within the cell. Human guanylate-binding protein 1 (hGBP1), the founding member of GBPs, is also engaged in the regulation of cell adhesion and migration. Here, we show how the GTPase cycle of farnesylated hGBP1 (hGBP1F) regulates its self-assembly and membrane interaction. Using vesicles of various sizes as a lipid bilayer model, we show GTP-dependent membrane binding of hGBP1F In addition, we demonstrate nucleotide-dependent tethering ability of hGBP1F Furthermore, we report nucleotide-dependent polymerization of hGBP1F, which competes with membrane binding of the protein. Our results show that hGBP1F acts as a nucleotide-controlled molecular switch by modulating the accessibility of its farnesyl moiety, which does not require any supportive proteins.
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