title: Toxoplasma gondii possesses a receptor for activated C kinase ortholog.
abstract: Receptor for activated C kinase 1 (RACK1) has been implicated in multiple protein-protein interactions including functioning as a scaffolding protein for signaling molecules. We report the cloning and cellular localization of a RACK1 ortholog (TgRACK1) in the opportunistic pathogen Toxoplasma gondii. The full-length transcript possesses a predicted ORF of 966 bp and codes for a protein of approximately 35 kDa molecular weight. Molecular analysis of TgRACK1 reveals the presence of seven WD40 repeat motifs. TgRACK1 was tagged with a FLAG epitope and stably expressed in RH parasites. FLAG-TgRACK1 localizes to the parasite cytoplasm and nucleus. Immunoprecipitation (IP) of FLAG-TgRACK1 from highly purified extracellular parasites followed by immunoblot analysis reveals an interaction between TgbetaCOP and FLAG-TgRACK1. This is the first demonstration of an interaction between a betaCOP subunit and the RACK1 protein. This result is of interest given that a signaling event precedes protein secretion and parasite invasion.
authors: Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556-0369, USA.
authors: Jennifer M
authors: JM
authors: Moran
authors: Sherri S
authors: SS
authors: Smith
authors: Kristin M
authors: KM
authors: Hager
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D000939:Epitopes / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009842:Oligopeptides; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014122:Toxoplasma / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D000939:Epitopes; D009842:Oligopeptides; D010455:Peptides; D015800:Protozoan Proteins; D000075370:Receptors for Activated C Kinase; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C085706:FLAG peptide