Molecular and immune response characterizations of a novel Bax inhibitor-1 gene in pufferfish, Takifugu obscurus

Abstract

Apoptosis plays a crucial role in many biological processes, including development, cellular homeostasis, and immune responses. Bax inhibitor-1 (BI-1) is an anti-apoptotic protein that protects cells from endoplasmic reticulum stress-induced apoptosis. In this study, a BI-1 gene from the pufferfish Takifugu obscurus (Pf-BI-1) was identified and characterized. The full length of Pf-BI-1 cDNA was 1387 bp, including a 5'-UTR of 82 bp, a 3'-UTR of 591 bp containing a poly-(A) tail, and an open reading frame (ORF) of 714 bp that encodes a polypeptide of 237 amino acids. Pf-BI-1 was ubiquitously expressed in various tissues, with the highest expression levels in the blood, brain, and gill. The expression of Pf-BI-1 was up-regulated in a time-dependent manner after heat shock stress, ammonia stress, and bacterial challenge. Intracellular localization revealed that Pf-BI-1 was primarily localized in the cell cytoplasm. Furthermore, over-expression of Pf-BI-1 could active NF-кB reporter genes in HeLa cells. These results indicated that Pf-BI-1 may be involved in the apoptosis and immunity process against ambient stressors in pufferfish.

Functional characterization of TNF‐α in pufferfish (Takifugu obscurus) in immune response and apoptosis against Aeromonas hydrophila

“…The mRNA expression was notably increased, indicating that ToTNFα might be involved in p53-related apoptosis. Further, the BI-1, an anti-apoptotic protein, was determined (Cheng et al, 2017). Our results showed that In summary, our research indicated that the ToTNFα was conserved in structural characterization and functional identification.…”

“…The mRNA expression was notably increased, indicating that ToTNF‐ α might be involved in p53 ‐related apoptosis. Further, the BI‐1, an anti‐apoptotic protein, was determined (Cheng et al., 2017). Our results showed that (r)ToTNF‐ α stimulation notably up‐regulated BI‐1 mRNA expression of head kidney leucocytes, indicating that ToTNF‐ α might induce apoptosis depending on anti‐apoptotic protein BI‐1 .…”

“…To determine the potential expression of ToTNF‐α in different tissues of pufferfish under normal physiological conditions, 10 tissues were collected, including muscle, intestine, anterior kidney, heart, blood, gills, liver, brain, spleen and skin, and frozen by liquid nitrogen immediately for RNA extraction (Cheng et al., 2017). Four parallel samples were collected for each tissue.…”

“…The tumour suppressor protein p53 is related to the activation of downstream signalling pathways and promotes TNF‐ α ‐induced apoptosis (Cheng et al., 2016; Goretsky et al., 2012). Further, Bax is involved in TNF‐ α ‐induced apoptosis (Li et al., 2013), and Bax inhibitor‐1 (BI‐1) functions as an anti‐apoptotic protein that maintains cells homeostasis and protects cells from Bax‐induced apoptosis (Cheng et al., 2017). Both p53 and BI‐1 play a vital role in apoptosis during many biological processes.…”