Signal recognition particle (SRP) and SRP receptor: A new paradigm for multistate regulatory GTPases

Shu Ou Shan, Sandra L. Schmid, Xin Zhang

Research output: Contribution to journalArticlepeer-review

28 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)6696-6704
Number of pages9
Issue number29
StatePublished - Jul 28 2009

All Science Journal Classification (ASJC) codes

  • Biochemistry


Dive into the research topics of 'Signal recognition particle (SRP) and SRP receptor: A new paradigm for multistate regulatory GTPases'. Together they form a unique fingerprint.

Cite this