AUTHOR=Huang Ying , Si Qin , Du Jie , Ren Qian 

TITLE=Yorkie Negatively Regulates the Expression of Antimicrobial Proteins by Inducing Cactus Transcription in Prawns Macrobrachium nipponense

JOURNAL=Frontiers in Immunology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2022.828271

DOI=10.3389/fimmu.2022.828271

ISSN=1664-3224

ABSTRACT=<p>The Hippo signaling pathway controls organ size and immune system in <italic>Drosophila</italic> and mammals. Yorkie acts as a transcriptional co-activator in the Hippo pathway and cross-talks with other essential pathways. In this study, a <italic>Yorkie</italic> gene and two <italic>Cactus</italic> isoforms (designated as <italic>MnYorkie</italic>, <italic>MnCactus-a</italic>, and <italic>MnCactus-b</italic>, respectively) were isolated and characterized from oriental river prawns (<italic>Macrobrachium nipponense</italic>). Results showed that <italic>MnYorkie</italic> includes 1620 bp open reading frame and encodes a protein of 539 amino acids (aa). <italic>MnCactus-a</italic> (377 aa) and <italic>MnCactus-b</italic> (471 aa) were produced by alternative splicing. <italic>MnYorkie</italic> and <italic>MnCactus</italic> were continuously expressed in all selected tissues. Upon Gram-positive bacterium <italic>Staphylococcus aureus</italic> and Gram-negative bacterium <italic>Vibrio parahaemolyticus</italic> stimulation, the mRNA levels of <italic>MnYorkie</italic> and <italic>MnCactus</italic> in hemocytes and intestines underwent time-dependent enhancement. RNA interference studies showed that <italic>MnYorkie</italic> silencing remarkably downregulated the transcription of <italic>MnCactus</italic> but upregulated the expression of seven immune-related genes. In addition, <italic>MnYorkie</italic> silencing <italic>in vivo</italic> decreased the susceptibility of prawns to bacterial challenge. After <italic>S. aureus</italic> and <italic>V. parahaemolyticus</italic> infection, the survival rate of prawns increased significantly from 2 to 6 days, which corresponded to the period of <italic>MnYorkie</italic> knockdown. All these findings suggested that <italic>MnYorkie</italic> in the Hippo pathway might exhibit remarkable biological roles in the immune defense of <italic>M. nipponense</italic> by negatively regulating the expression of immune-related genes and promoting the transcription of <italic>MnCactus</italic>.</p>