Related Experiment Video
Updated: Jul 5, 2026

Comparing the Affinity of GTPase-binding Proteins using Competition Assays
Published on: October 8, 2015
Cofactor dependent conformational switching of GTPases
Vasili Hauryliuk1, Sebastian Hansson, Måns Ehrenberg
1Department of Cell and Molecular Biology, Molecular Biology Program, Uppsala University, Uppsala, Sweden.
This study presents a generalized scheme for GTPase action, refining models of guanine nucleotide exchange. It incorporates cofactors for conformational switching, offering a more nuanced view of regulation for small GTPases.
Area of Science:
- Biochemistry
- Structural Biology
- Molecular Biology
Background:
- Small GTPases are crucial regulators of cellular processes.
- Existing models of GDP/GTP exchange in GTPases rely on specific assumptions about conformational switching and regulation by guanine nucleotide exchange factors (GEFs).
Purpose of the Study:
- To present a generalized scheme for GTPase action that accounts for recent biochemical and structural data.
- To provide a more nuanced understanding of nucleotide exchange regulation in GTPases, including the role of cofactors.
Main Methods:
- Theoretical analysis of structural and biochemical data.
- Development of a generalized scheme for GTPase action.
Main Results:
- The proposed scheme integrates cofactor-dependent conformational switching with nucleotide exchange.
- It offers a more comprehensive model that challenges previous assumptions about GTPase regulation.
- The scheme aids in interpreting experiments involving GTP analogs.
Conclusions:
- Current models of GTPase regulation may be oversimplified.
- A generalized scheme incorporating cofactors provides a more accurate framework for understanding GTPase function.
- This work clarifies potential issues in interpreting experimental data on nucleotide exchange mechanisms.
More Related Videos
Related Concept Videos
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...
GTPases and their Regulation
Large G-proteins, also known...
GTPases and their Regulation
Large G-proteins, also known...
Activation and Inactivation of G Proteins
Small GTPases - Ras and Rho
Three regulatory proteins control their activity:
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...

