Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published July 28, 2009 | Accepted Version
Journal Article Open

Signal Recognition Particle (SRP) and SRP Receptor: A New Paradigm for Multistate Regulatory GTPases


The GTP-binding proteins or GTPases comprise a superfamily of proteins that provide molecular switches in numerous cellular processes. The "GTPase switch" paradigm, in which a GTPase acts as a bimodal switch that is turned "on" and "off" by external regulatory factors, has been used to interpret the regulatory mechanism of many GTPases for more than two decades. Nevertheless, recent work has unveiled an emerging class of "multistate" regulatory GTPases that do not adhere to this classical paradigm. Instead of relying on external nucleotide exchange factors or GTPase activating proteins to switch between the on and off states, these GTPases have the intrinsic ability to exchange nucleotides and to sense and respond to upstream and downstream factors. In contrast to the bimodal nature of the GTPase switch, these GTPases undergo multiple conformational rearrangements, allowing multiple regulatory points to be built into a complex biological process to ensure the efficiency and fidelity of the pathway. We suggest that these multistate regulatory GTPases are uniquely suited to provide spatial and temporal control of complex cellular pathways that require multiple molecular events to occur in a highly coordinated fashion.

Additional Information

© 2009 American Chemical Society. Received April 23, 2009; Revised Manuscript Received May 25, 2009. We thank Thomas Pucadyil, Marcel Mettlen, and members of the Shan laboratory for helpful comments on the manuscript.

Attached Files

Accepted Version - nihms204160.pdf


Files (1.5 MB)
Name Size Download all
1.5 MB Preview Download

Additional details

August 20, 2023
October 19, 2023