Molecular Characterization of Paralichthys olivaceus MAF1 and Its Potential Role as an Anti-Viral Hemorrhagic Septicaemia Virus Factor in Hirame Natural Embryo Cells

Abstract

MAF1 is a global suppressor of RNA polymerase III-dependent transcription, and is conserved from yeast to human. Growing evidence supports the involvement of MAF1 in the immune response of mammals, but its biological functions in fish are unknown. We isolated and characterized Maf1 from the olive flounder Paralichthys olivaceus (PoMaf1). The coding region of PoMaf1 comprised 738 bp encoding a 245-amino-acid protein. The deduced PoMAF1 amino acid sequence shared features with those of MAF1 orthologues from vertebrates. PoMaf1 mRNA was detected in all tissues examined, and the levels were highest in eye and muscle tissue. The PoMaf1 mRNA level increased during early development. In addition, the PoMaf1 transcript level decreased during viral hemorrhagic septicemia virus (VHSV) infection of flounder hirame natural embryo (HINAE) cells. To investigate the role of PoMaf1 in VHSV infection, single-cell-derived PoMaf1 knockout HINAE cells were generated using the clustered regularly interspaced short palindromic repeats/CRISPR-associated-9 (CRISPR/Cas9) system, and cell clones with complete disruption of PoMaf1 were selected. PoMaf1 disruption increased the VHSV glycoprotein (G) mRNA levels during VHSV infection of HINAE cells, implicating PoMAF1 in the immune response to VSHV infection. To our knowledge, this is the first study to characterize fish Maf1, which may play a role in the response to viral infection.

Genome‐wide identification of catfish antimicrobial peptides: A new perspective to enhance fish disease resistance

“…In a second case of Chinook salmon cell line, knockout of stat2 increased viral resistance as seen the increased production of viral particles of the DNA virus, epizootic haematopoietic necrosis virus, and the RNA virus, salmon pancreatic disease virus, but less ssRNA viral particles, VHSV 201 . In a third hirame natural embryo cell line of Japanese flounder, knockout PoMaf1 (an RNA polymerase [pol] III‐associated transcription repressor) using CRISPR/Cas9 increased the VHSV glycoprotein (G) mRNA levels during VHSV infection 202 . Although CRISPR/cas9 technology has been successfully applied in the research of disease‐resistant enhancement of aquatic animals, further pathogen infection experiments in vivo are needed to verify its value regarding knock out of AMGs and other immune‐associated/responsive genes that could potentially increase disease resistance for specialized cases.…”

CRISPR-Cas Genome Editing Technique for Fish Disease Management: Current Study and Future Perspective

“…Many reputable shellfish farms report shellfish dying overnight because of viral assaults. In fish aquaculture, reproduction, and development [ 41 , 42 ], growth [ 43 ], pigment [ 44 , 45 ], disease resistance [ 46 ], trans-GFP usage in research [ 47 ], and omega-3 metabolism [ 48 , 49 ] are the qualities that are most often targeted for genetic engineering [ 50 ]. However, using molecular biological techniques to resolve diseases has become a core technology.…”

How to Shut Down Transcription in Archaea During Virus Infection

“…The negative elongation factor (NELF) enables promoter-proximal pausing of RNAPII, and plays an important role in viral latency during HIV (human immunodeficiency virus) infection [19,20]. Finally, MAF1 binds directly to RNAPIII and inhibits it, while also interacting with mTOR and thereby indirectly activating the host immune response [21][22][23][24] .…”