| Neural precursor cell expressed developmentally down regulated 8(NEDD8)is a ubiquitin-like protein that activates Cullin-RING ligases and modifies substrates via Neddylation.However,there is limited information on how Neddylation regulates innate immunity in crustaceans.Therefore,we have studied the important functions of Neddylation in the antibacterial immunity of Eriocheir sinensis,an important freshwater cultured species in China.These results will help to better understand the innate immunity of invertebrates and provide theoretical support for the solution of bacterial diseases in the Chinese mitten crab breeding industry.In the present study,we identified the evolutionarily conserved NEDD8 with the ubiquitin homologue domain in the Chinese mitten crab(Eriocheir sinensis),named it Es NEDD8.Then,we analyzed the expression patterns and cellular location of its substrates,EsCullin family.qRT-PCR showed that both EsNEDD8 and EsCullin family were widely expressed in all the selected tissues.EsCullin family presents patterns of different trends in hemocytes after bacterial injection.Moreover,silencing of Es Cullin family significantly suppressed the expression of antimicrobial peptides(AMPs)in the hemocytes after bacterial stimulation,and inhibition of EsCullins neddylation by treatment with the NEDD8-activating enzyme inhibitor MLN4924 significantly inhibited the expression of AMPs.Subsequently,we found that inhibition of Neddylation modification inhibited the phosphorylation level of ERK and the transcription factor Dorsal translocated into nucleus was also inhibited.Thus,the results show that Neddylation pathway could control antimicrobial activities via mediated transcription factor Dorsal tranlacation to regulate AMPs expression in the Chinese mitten crab. |
