PtGtsf1 was fused with FlagHA and induced to express in Paramecium tetraurelia. The interacted proteins of PtGtsf1 was obtained by immunoprecipitation with anti-HA antibody, followed with mass spectrometry to identify the proteins. Meanwhile, FlagHA without PtGtsf1 was expressed in Paramecium tetraurelia as control and was performed with same procedures as PtGtsf1-FlagHA. By comparing the enrichment of proteins in PtGtsf1-FlagHA and control, the interacted proteins of PtGtsf1 in Paramecium tetraurelia were identified.