PDI family thioredoxin from disk abalone (Haliotis discus discus): Responses to stimulants (PAMPs, bacteria, and viral) and functional characterization

D S Liyanage; W K M Omeka; W M Gayashani Sandamalika; H M V Udayantha; Taehyug Jeong; Sukkyoung Lee; Jehee Lee

doi:10.1016/j.fsi.2021.11.037

PDI family thioredoxin from disk abalone (Haliotis discus discus): Responses to stimulants (PAMPs, bacteria, and viral) and functional characterization

Fish Shellfish Immunol. 2022 Jan:120:261-270. doi: 10.1016/j.fsi.2021.11.037. Epub 2021 Nov 27.

Authors

D S Liyanage¹, W K M Omeka¹, W M Gayashani Sandamalika¹, H M V Udayantha¹, Taehyug Jeong², Sukkyoung Lee³, Jehee Lee⁴

Affiliations

¹ Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea.
² Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea; Marine Science Institute, Jeju National University, Jeju, 63333, Republic of Korea.
³ Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea; Marine Science Institute, Jeju National University, Jeju, 63333, Republic of Korea. Electronic address: sukkyoung@jejunu.ac.kr.
⁴ Department of Marine Life Sciences & Fish Vaccine Research Center, Jeju National University, Jeju, 63243, Republic of Korea; Marine Science Institute, Jeju National University, Jeju, 63333, Republic of Korea. Electronic address: jehee@jejunu.ac.kr.

PMID: 34848304
DOI: 10.1016/j.fsi.2021.11.037

Abstract

Thioredoxin, a highly conserved class of proteins involved in redox signaling, is found in a range of organisms from bacteria to higher-level eukaryotes. Thioredoxin acts as an active regulatory enzyme to eliminate excessive reactive oxygen species, thereby preventing cellular damage. In this study, the cDNA sequence of thioredoxin domain-containing 5 (AbTXNDC5) from the disk abalone transcriptomic database was characterized. An in silico analysis of AbTXNDC5 was performed, and its spatial and temporal expression patterns in hemocytes and gills in response to bacteria (Vibrio parahaemolyticus, Listeria monocytogenes), viral hemorrhagic septicemia virus, and pathogen-associated molecular pattern molecules were observed. Furthermore, AbTXNDC5 expression was examined in different developmental stages. Functional assays to explore insulin disulfide reduction, anti-apoptotic activity, and protection against hypoxic cell death of AbTXNDC5 were conducted through recombinant proteins or overexpression in cells. AbTXNDC5 contains a 1179-bp open reading frame coding for 392 amino acids. Conserved thiol-disulfide cysteine residues within two Cys-X-X-Cys motifs were found in AbTXNDC5. Quantitative real-time polymerase chain reaction indicated that healthy digestive tract and hemocyte tissues expressed high levels of AbTXNDC5 mRNA, which may protect the host from invading pathogens. Immune-challenged abalone hemocytes and gills exhibited upregulated expression of AbTXNDC5 at different time points. rAbTXNDC5 also exhibited a functional insulin disulfide reductase activity. AbTXNDC5 conferred protection to cultured cells from apoptosis and hypoxia-induced stress_, compared to the pcDNA3.1⁽⁺⁾ transfected control cells. Therefore, AbTXNDC5 can be considered an important gene in abalones in relation to the primary immune system and regulation of redox homeostasis and confers protection from stress.

Keywords: Antioxidant; Haliotis discus discus; Immune stimulation; Oxidative stress; Thioredoxin domain-containing 5.

MeSH terms

Amino Acid Sequence
Animals
Disulfides*
Gastropoda* / genetics
Gene Expression Regulation
Insulins*
Listeria monocytogenes
Novirhabdovirus
Pathogen-Associated Molecular Pattern Molecules
Phylogeny
Thioredoxins* / genetics
Vibrio parahaemolyticus

Substances

Disulfides
Insulins
Pathogen-Associated Molecular Pattern Molecules
Thioredoxins