E. chaffeensis TRP120 interactions with multiple human proteins detected by chemiluminescent coimmunoprecipitation. AcGFP1 (without insert) or AcGFP1-TRP120 was coexpressed with the PL-ACTG1, -GGA1, -PCGF5, or -UNC13D fusion protein in HeLa cells. A positive control (B, controls, right bars in the pair of bars) was performed by coexpressing AcGFP1-p53 (human tumor suppressor p53 protein) and PL-T (simian virus 40 large T antigen), while AcGFP1-TRP120 (B, controls, left bars in the pair of bars), -TRP120N, -TRP120TR, or -TRP120C (C, controls, from left to right) was coexpressed with PL (without insert) as the negative control. ProLabel activity in relative light units (RLUs) was measured 1 h after addition of substrate. The results were from three independent experiments, and the values are means ± standard deviations. (A) The relative strength of expression of four proteins (ACTG1, GGA1, PCGF5, and UNC13D) was detected in HeLa cells by PL chemiluminescence activity. Control, pPL-C. (B) Relative strength and interaction of AcGFP1-TRP120 with PL-ACTG1, -GGA1, -PCGF5, or -UNC13D. (C) Relative strength and interaction of AcGFP1-TRP120N, -TRP120TR, and -TRP120C with PL-ACTG1, -GGA1, -PCGF5, or -UNC13D. TRP120N, amino-terminal TRP120; TRP120TR, tandem repeats of TRP120; TRP120C, carboxyl-terminal TRP120.