Quantitative Analysis of Prenylated RhoA Interaction with Its Chaperone, RhoGDI

A1 Originalartikel i en vetenskaplig tidskrift (referentgranskad)

Interna författare/redaktörer

Publikationens författare: Tnimov Z, Guo Z, Gambin Y, Nguyen UTT, Wu YW, Abankwa D, Stigter A, Collins BM, Waldmann H, Goody RS, Alexandrov K
Publiceringsår: 2012
Tidskrift: Journal of Biological Chemistry
Tidskriftsakronym: J BIOL CHEM
Volym: 287
Nummer: 32
Artikelns första sida, sidnummer: 26549
Artikelns sista sida, sidnummer: 26562
Antal sidor: 14
ISSN: 0021-9258


Small GTPases of the Rho family regulate cytoskeleton remodeling, cell polarity, and transcription, as well as the cell cycle, in eukaryotic cells. Membrane delivery and recycling of the Rho GTPases is mediated by Rho GDP dissociation inhibitor (RhoGDI), which forms a stable complex with prenylated Rho GTPases. We analyzed the interaction of RhoGDI with the active and inactive forms of prenylated and unprenylated RhoA. We demonstrate that RhoGDI binds the prenylated form of RhoA center dot GDP with unexpectedly high affinity (K-d = 5 pM). The very long half-life of the complex is reduced 25-fold on RhoA activation, with a concomitant reduction in affinity (K-d = 3 nM). The 2.8-angstrom structure of the RhoA center dot guanosine 5'-[beta,gamma-imido] triphosphate (GMPPNP)center dot RhoGDI complex demonstrated that complex formation forces the activated RhoA into a GDP-bound conformation in the absence of nucleotide hydrolysis. We demonstrate that membrane extraction of Rho GTPase by RhoGDI is a thermodynamically favored passive process that operates through a series of progressively tighter intermediates, much like the one that is mediated by RabGDI.

Senast uppdaterad 2020-31-05 vid 05:58