Role of Magnesium in Nucleotide Exchange on the Small G Protein Rac Investigated Using Novel Fluorescent Guanine Nucleotide Analogues†

Biochemistry ◽  
2002 ◽  
Vol 41 (11) ◽  
pp. 3828-3835 ◽  
Author(s):  
Adam Shutes ◽  
Robert A. Phillips ◽  
John E. T. Corrie ◽  
Martin R. Webb
Keyword(s):  
G Protein ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Nucleotide Analogues ◽  
Small G Protein

scholarly journals Activation of G proteins by guanine nucleotide exchange factors relies on GTPase activity

2015 ◽  
Author(s):  
Rob J Stanley ◽  
Geraint MH Thomas
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Guanine Nucleotide Exchange Factors ◽  
Guanine Nucleotide ◽  
Gtpase Activity ◽  
Nucleotide Exchange ◽  
Signalling Molecules ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors ◽  
Experimental Strategies

G proteins are an important family of signalling molecules controlled by guanine nucleotide exchange and GTPase activity in what is commonly called an 'activation/inactivation cycle'. The molecular mechanism by which guanine nucleotide exchange factors (GEFs) catalyse the activation of monomeric G proteins is well-established, however the complete reversibility of this mechanism is often overlooked. Here, we use a theoretical approach to prove that GEFs are unable to positively control G protein systems at steady-state in the absence of GTPase activity. Instead, positive regulation of G proteins must be seen as a product of the competition between guanine nucleotide exchange and GTPase activity -- emphasising a central role for GTPase activity beyond merely signal termination. We conclude that a more accurate description of the regulation of G proteins via these processes is as a 'balance/imbalance' mechanism. This result has implications for the understanding of many intracellular signalling processes, and for experimental strategies that rely on modulating G protein systems.

scholarly journals Regulation of the G-protein Regulatory-GαiSignaling Complex by Nonreceptor Guanine Nucleotide Exchange Factors

2012 ◽  
Vol 288 (5) ◽  
pp. 3003-3015 ◽  
Author(s):  
Sukru Sadik Oner ◽  
Ellen M. Maher ◽  
Meital Gabay ◽  
Gregory G. Tall ◽  
Joe B. Blumer ◽  
...  
Keyword(s):  
G Protein ◽  
Guanine Nucleotide Exchange Factors ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors
Sign in / Sign up

Export Citation Format

Share Document