부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jmb.2009.07.076 Byline: Erin J. Friedman (1), Brenda R.S. Temple (2)(3), Stephanie N. Hicks (4), John Sondek (3)(4)(5), Corbin D. Jones (1)(6), Alan M. Jones (1)(4) Keywords: heterotrimeric G-proteins; phospholipase C-[beta]2; protein surface evolution; interface prediction; PLC-[beta]2-G[beta][gamma] interaction interface Abbreviations: G-protein, guanine nucleotide-binding protein; GRK, G-protein-coupled receptor kinase; MSA, multiple sequence alignment; PLC-[beta]2, phospholipase C [beta]2; RGS9, regulator of G-protein signaling 9; ROI, region of interest; RSA, relative solvent accessibility Abstract: G[beta] subunits from heterotrimeric G-proteins (guanine nucleotide-binding proteins) directly bind diverse proteins, including effectors and regulators, to modulate a wide array of signaling cascades. These numerous interactions constrained the evolution of the molecular surface of G[beta]. Although mammals contain five G[beta] genes comprising two classes (G[beta]1-like and G[beta]5-like), plants and fungi have a single ortholog, and organisms such as Caenorhabditis elegans and Drosophila melanogaster contain one copy from each class. A limited number of crystal structures of complexes containing G[beta] subunits and complementary biochemical data highlight specific sites within G[beta]s needed for protein interactions. It is difficult to determine from these interaction sites what, if any, additional regions of the G[beta] molecular surface comprise interaction interfaces essential to G[beta]'s role as a nexus in numerous signaling cascades. We used a comparative evolutionary approach to identify five known and eight previously unknown putative interfaces on the surface of G[beta]. We show that one such novel interface occurs between G[beta] and phospholipase C [beta]2 (PLC-[beta]2), a mammalian G[beta] interacting protein. Substitutions of residues within this G[beta]-PLC-[beta]2 interface reduce the activation of PLC-[beta]2 by G[beta]1, confirming that our de novo comparative evolutionary approach predicts previously unknown G[beta]-protein interfaces. Similarly, we hypothesize that the seven remaining untested novel regions contribute to putative interfaces for other G[beta] interacting proteins. Finally, this comparative evolutionary approach is suitable for application to any protein involved in a significant number of protein-protein interactions. Author Affiliation: (1) Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA (2) The R. L. Juliano Structural Bioinformatics Core Facility, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA (3) Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA (4) Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA (5) Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA (6) Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA Article History: Received 10 February 2009; Revised 8 July 2009; Accepted 27 July 2009 Article Note: (miscellaneous) Edited by M. Sternberg