TY - JOUR
T1 - The Toxoplasma pseudokinase ROP5 forms complexes with ROP18 and ROP17 kinases that synergize to control acute virulence in mice
AU - Etheridge, Ronald D.
AU - Alaganan, Aditi
AU - Tang, Keliang
AU - Lou, Hua Jane
AU - Turk, Benjamin E.
AU - Sibley, L. David
N1 - Funding Information:
We thank Vern Carruthers, Dick Schaap, Ray Hui, Greg Taylor, Herbert Virgin, and Mary Dinauer for generously providing reagents and Sebastian Lourido, Asis Khan, and members of the Sibley lab for many helpful discussions. Histological studies were performed by the Digestive Diseases Research Core Centers at Washington University, and slides were analyzed by Suellen Greco, Comparative Animal Medicine, Washington University School of Medicine. Mass spectrometry was performed by Sophie Alvarez, Danforth Plant Sciences. This work was supported by grants from the National Institutes of Health ( www.nih.gov ) (AI082423, AI036629, P30 DK52574, and GM104047). R.D.E. was partially supported by an NRSA award from the National Institutes of Health (F32 AI096853-02). The funders had no role in the study design, data collection, decision to publish, or preparation of the manuscript.
PY - 2014/5/14
Y1 - 2014/5/14
N2 - Polymorphic rhoptry-secreted kinases (ROPs) are essential virulence factors of Toxoplasma gondii. In particular, the pseudokinase ROP5 is the major determinant of acute virulence in mice, but the underlying mechanisms are unclear. We developed a tandem affinity protein tagging and purification approach in T. gondii and used it to show that ROP5 complexes with the active kinases ROP18 and ROP17. Biochemical analyses indicate that ROP18 and ROP17 have evolved to target adjacent and essential threonine residues in switch region I of immunity-related guanosine triphosphatases (GTPases) (IRGs), a family of host defense molecules that function to control intracellular pathogens. The combined activities of ROP17 and ROP18 contribute to avoidance of IRG recruitment to the intracellular T. gondii-containing vacuole, thus protecting the parasite from clearance in interferon-activated macrophages. These studies reveal an intricate, multilayered parasite survival strategy involving pseudokinases that regulate multiple active kinase complexes to synergistically thwart innate immunity.
AB - Polymorphic rhoptry-secreted kinases (ROPs) are essential virulence factors of Toxoplasma gondii. In particular, the pseudokinase ROP5 is the major determinant of acute virulence in mice, but the underlying mechanisms are unclear. We developed a tandem affinity protein tagging and purification approach in T. gondii and used it to show that ROP5 complexes with the active kinases ROP18 and ROP17. Biochemical analyses indicate that ROP18 and ROP17 have evolved to target adjacent and essential threonine residues in switch region I of immunity-related guanosine triphosphatases (GTPases) (IRGs), a family of host defense molecules that function to control intracellular pathogens. The combined activities of ROP17 and ROP18 contribute to avoidance of IRG recruitment to the intracellular T. gondii-containing vacuole, thus protecting the parasite from clearance in interferon-activated macrophages. These studies reveal an intricate, multilayered parasite survival strategy involving pseudokinases that regulate multiple active kinase complexes to synergistically thwart innate immunity.
UR - http://www.scopus.com/inward/record.url?scp=84901029147&partnerID=8YFLogxK
U2 - 10.1016/j.chom.2014.04.002
DO - 10.1016/j.chom.2014.04.002
M3 - Article
C2 - 24832449
AN - SCOPUS:84901029147
SN - 1931-3128
VL - 15
SP - 537
EP - 550
JO - Cell Host and Microbe
JF - Cell Host and Microbe
IS - 5
ER -