GTPase-activating protein

GTPase-activating proteins or GTPase-accelerating proteins (GAPs) are a family of regulatory proteins whose members can bind to activated G proteins and stimulate their GTPase activity, with the result of terminating the signaling event.[1] GAPs are also known as RGS protein, or RGS proteins,[2] and these proteins are crucial in controlling the activity of G proteins. Regulation of G proteins is important because these proteins are involved in a variety of important cellular processes. The large G proteins, for example, are involved in transduction of signaling from the G protein-coupled receptor for a variety of signaling processes like hormonal signaling,[2] and small G proteins are involved in processes like cellular trafficking and cell cycling.[3] GAP's role in this function is to turn the G protein's activity off. In this sense, GAPs function is opposite to that of guanine nucleotide exchange factors (GEFs), which serve to enhance G protein signaling.[4]

  1. ^ Gerhard Krauss (2008). Biochemistry of signal transduction and regulation. Wiley-VCH. pp. 235–. ISBN 978-3-527-31397-6. Retrieved 15 December 2010.
  2. ^ a b Kimple, A.J. "Structural Determinants of G-protein α Subunit Selectivity by Regulator of G-protein Signaling 2 (RGS2)". The Journal of Biological Chemistry. 284 (2009): 19402-19411.
  3. ^ Xu, Haiming et al. "Loss of the Rho GTPase Activating Protein p190-B Enhances Hematopoietic Stem Cell Engraftment Potential". Blood. 114 (2009): 3557–3566.
  4. ^ Krendel, M. "Nucleotide Exchange Factor GEF-H1 Mediates Cross-Talk between Microtubules and the Actin Cytoskeleton". Nature Cell Biology. 4 (2002): 294–301.