FIG 1.

MYR1-3×HA immunoprecipitation identifies many MYR1-associating Toxoplasma proteins. (A) Schematic of MYR1 IP-MS work flow. (B) Results of IP-MS analysis. Mass spectrometry was performed on immunoprecipitated material as depicted in panel A, and the number of spectral counts was determined for all identified proteins. This experiment was performed twice (IP 1 and IP 2) for both RH::MYR1-3×HA and an RHΔhpt untagged control. The Toxoplasma proteins identified from the two experiments were ranked according to the average NSAF enrichment in the MYR1-3×HA-expressing strain relative to that for the untagged RH control after adding a nominal single count to all results, enabling a ratio to be determined (Enrichment and Rank). The full data set, including associating host proteins, is presented in Data Set S1 in the supplemental material. Displayed here are the majority Toxoplasma protein identifiers (TGGT1_), i.e., the proteins that contained at least half of the peptides belonging to a group of proteins that could not be unambiguously identified by unique peptides; the descriptive name for each protein (Description); and the corresponding number of spectral counts detected (Total MS/MS count) for all Toxoplasma proteins with an average enrichment score of greater than 10. Also shown are data for the proteins GRA45, MYR3, and ROP17. The proteins whose genes chosen for subsequent disruption are highlighted in orange.