Molecular cloning and function of two tumor necrosis factor receptor-associated factors genes (TRAF2 and TRAF4) from Pinctada fucata martensii

Abstract

Tumor necrosis factor receptor-associated factors (TRAFs) have been studied in a few mollusks and participate in various biological processes, like apoptosis, immune response, stress, and inflammatory response. However, TRAFs’ function and mechanism of pearl oysters (Pinctada fucata martensii) are still unclear. In this study, we identified novel PmTRAF2 and PmTRAF4 from P. f. martensii. The deduced PmTRAF2 and PmTRAF4 proteins contain TRAF-type zinc finger domain and MATH domain, while PmTRAF4 lacks a RING finger domain. Multiple sequence alignment revealed that PmTRAF2 and PmTRAF4 had high homology with the ortholog of other species. Phylogenic analysis indicated that PmTRAF4 was closer to the homolog protein of Mytilus edulis and Mytilus galloprovincialis, and PmTRAF2 was closer to Crassostrea gigas TRAF2. The real-time quantitative PCR (qPCR) analysis revealed that PmTRAF2 and PmTRAF4 were expressed in all six tissues, and both of them were significantly expressed in hepatopancreas and gill (p < 0.01). Under lipopolysaccharide (LPS) stimulation, polyinosinic acid (PolyI:C) stimulation, and nucleus insertion surgery, the transcripts of PmTRAF2, PmTRAF3, PmTRAF4 and PmTRAF6 in hepatopancreas were markedly changed at corresponding time points. These results have indicated that these genes may play a role in P. f. martensii innate immunity. Yeast two-hybrid assays show that PmTRAF2 interacts with PmTRAF6 but not PmTRAF3, potentially affecting downstream immune signaling pathways. Our findings provide new perspectives for further investigation of TRAFs’ immune mechanisms in bivalves.

Unlocking hepatocellular carcinoma aggression: STAMBPL1-mediated TRAF2 deubiquitination activates WNT/PI3K/NF-kb signaling pathway

“…TRAF2 is involved in the signaling pathways of tumor necrosis factor receptors (TNFRs), which can induce either cell survival or apoptotic cell death. Studies have shown that TRAF2 can interact with other proteins, such as TRAF6, which can affect the downstream immune signaling in the various cellular processes [ 25 ]. The dynamics of TRAF2 are influenced by the length of its tail, with longer tails affecting the dynamics of the globular regions in the protein's C-terminal head [ 26 ].…”