TY - JOUR
T1 - Structural determinants of rgs-rhogef signaling critical to entamoeba histolytica pathogenesis
AU - Bosch, Dustin E.
AU - Kimple, Adam J.
AU - Manning, Alyssa J.
AU - Muller, Robin E.
AU - Willard, Francis S.
AU - MacHius, Mischa
AU - Rogers, Stephen L.
AU - Siderovski, David P.
N1 - Funding Information:
We thank Dr. William Petri (UVa) for provision of E. histolytica genomic DNA and RNA and Dr. Michael Miley (UNC) for crystallographic assistance. Crystallographic data were collected at the Advanced Photon Source (Argonne National Labs) 23-IDD beamline. This work was supported by NIH grant GM082892 (to D.P.S.); an NIGMS MSTP award (T32 GM008719) and individual F30 NRSA fellowships MH074266 (to A.J.K.); and DK091978 (to D.E.B.).
PY - 2013/1/8
Y1 - 2013/1/8
N2 - G protein signaling pathways, as key components of physiologic responsiveness and timing, are frequent targets for pharmacologic intervention. Here, we identify an effector for heterotrimeric G protein α subunit (EhGα1) signaling from Entamoeba histolytica, the causative agent of amoebic colitis. EhGα1 interacts with this effector and guanosine triphosphatase-accelerating protein, EhRGS-RhoGEF, in a nucleotide state-selective fashion. Coexpression of EhRGS-RhoGEF with constitutively active EhGα1 and EhRacC leads to Rac-dependent spreading in Drosophila S2 cells. EhRGS-RhoGEF overexpression in E. histolytica trophozoites leads to reduced migration toward serum and lower cysteine protease activity, as well as reduced attachment to, and killing of, host cells. A 2.3 Å crystal structure of the full-length EhRGS-RhoGEF reveals a putative inhibitory helix engaging the Dbl homology domain Rho-binding surface and the pleckstrin homology domain. Mutational analysis of the EhGα1/EhRGS-RhoGEF interface confirms a canonical "regulator of G protein signaling" domain rather than a RhoGEF-RGS ("rgRGS") domain, suggesting a convergent evolution toward heterotrimeric and small G protein cross-talk.
AB - G protein signaling pathways, as key components of physiologic responsiveness and timing, are frequent targets for pharmacologic intervention. Here, we identify an effector for heterotrimeric G protein α subunit (EhGα1) signaling from Entamoeba histolytica, the causative agent of amoebic colitis. EhGα1 interacts with this effector and guanosine triphosphatase-accelerating protein, EhRGS-RhoGEF, in a nucleotide state-selective fashion. Coexpression of EhRGS-RhoGEF with constitutively active EhGα1 and EhRacC leads to Rac-dependent spreading in Drosophila S2 cells. EhRGS-RhoGEF overexpression in E. histolytica trophozoites leads to reduced migration toward serum and lower cysteine protease activity, as well as reduced attachment to, and killing of, host cells. A 2.3 Å crystal structure of the full-length EhRGS-RhoGEF reveals a putative inhibitory helix engaging the Dbl homology domain Rho-binding surface and the pleckstrin homology domain. Mutational analysis of the EhGα1/EhRGS-RhoGEF interface confirms a canonical "regulator of G protein signaling" domain rather than a RhoGEF-RGS ("rgRGS") domain, suggesting a convergent evolution toward heterotrimeric and small G protein cross-talk.
UR - http://www.scopus.com/inward/record.url?scp=84872161507&partnerID=8YFLogxK
U2 - 10.1016/j.str.2012.11.012
DO - 10.1016/j.str.2012.11.012
M3 - Article
C2 - 23260656
AN - SCOPUS:84872161507
SN - 0969-2126
VL - 21
SP - 65
EP - 75
JO - Structure
JF - Structure
IS - 1
ER -