SUMOylation Affects Aggregation of PKCθ at the Immunological Synapse When Ubc9 Is Fusion Expressed

Abstract: SUMOylation has diverse functions， including regulating the neural synapse formation and transmission. The neural and immunological synapses share common features， while protein kinase Cθ (PKCθ) is the only PKC (protein kinase C) isoform which is localized in the cSMAC of the immunological synapse following antigen stimulation. To unravel the effects of sumoylation on the immunological synapse， this study measured the interaction between Ubc9-PKCθ and SUMO by Ubc9 fusion-directed SUMOylation system (UFDS)， constructed multipoint KR mutant of Ubc9-PKCθ by PCR site-directed mutagenesis， observed the contact surface between Raji B and Jurkat T cells by fluorescence microscope. The results showed that Ubc9-PKCθ could be modified by SUMO， and accumulated at the immunological synapse after antigen stimulation. Furthermore， after multiple SUMOylation sites were mutated， the sumoylated Ubc9-PKCθ had a significant reduction， and was still targeted to the immunological synapse but displayed a diffuse pattern. In conclusion， SUMOylation can affect aggregation of PKCθ at the immunological synapse when Ubc9 is fusion expressed.

CSTR: 32200.14.cjcb.2018.06.0018