Identification of RNF114 as a novel positive regulatory protein for T cell activation.

RNF114 [RING (really interesting new gene) finger protein 114] has been shown to be a novel psoriasis susceptibility gene, with a putative role in the regulation of immune responses, though the underlying mechanism was not fully identified. In the present study, to investigate whether RNF114 is involved in T cell activation, a series of fluorescence activated cell sortings (FACS) were performed. The analysis confirmed that RNF114 over-expression had a promotion effect on T cell activation with an average 43.97% increment and the upregulatory roles showed a dose-dependent effect with 18.44% increment. Interestingly, the two C2H2 domains were shown to play important but opposite roles in T cell activation. The deficiency of upstream C2H2 domain increased the efficiency of T cell activation by 12.81%, while the downstream C2H2 domain alone promoted it with an average level 25.12% higher than intact RNF114 protein. Combined with tandem affinity purification (TAP) and mass spectrometry, our investigations found 23 RNF114-interacting proteins that have distinct physiological roles in transcription, translation, DNA repair and signaling pathways. These findings, including recognition of RNF114 as a positive regulatory protein and identification of its interacting proteins, widen the understanding for investigating functions of RNF114 involved in T cell activation.