SIKE affects processes involving cytoskeletal rearrangement

Suppressor of IKK Epsilon (SIKE) is a protein in the virus‐ and TRL3‐triggered cascading signal pathway. SIKE has been shown to directly interact with alpha‐actinin, a protein involved in cytoskeletal rearrangement, in coimmunoprecipitation and in vitro precipitation experiments. However, the exact cellular processes SIKE affects are still unknown. To bridge this gap, we examined two processes that require cytoskeletal rearrangement, migration and phagocytosis, to determine if SIKE functions in these processes. Our model system is a parental cell line, HAP1, and a CRISPR/Cas9 knockout of SIKE, SIKE‐CR. Scratch assays were performed on parental HAP1 cells and SIKE knockout cells. To induce an anti‐viral response, dsRNA, a viral mimic, was applied to cells prior to the start of scratch assays in a second set of experiments. Phagocytosis assays, using latex beads coated with FITC labeled IgG, were performed and analyzed with a novel ImageJ procedure to determine the effects of SIKE on phagocytosis. The scratch assays indicate that loss of SIKE decreases cellular motility by ~30% whereas SIKE decreases cellular ability to perform phagocytosis. These studies suggest that SIKE links the innate immune system's antiviral response to cytoskeletal rearrangements necessary to host defenses. Support or Funding Information Studies were funded by USD SURE and NIH‐NIAID R21 to JKB. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .