Related Experiment Video
Updated: Jun 2, 2026
In vivo Imaging Method to Distinguish Acute and Chronic Inflammation
Published on: August 16, 2013
A macrophage migration inhibitory factor like oxidoreductase from pearl oyster Pinctada fucata involved in innate
Shuge Cui1, Dianchang Zhang, Shigui Jiang
1School of Life Science and Technology, Jinan University, Guangzhou 510632, China.
Abstract:
Macrophage migration inhibitory factor (MIF) is an important cytokine and plays a crucial role as a pivotal regulator of innate immunity. In this study, a MIF cDNA was identified and characterized from the pearl oyster Pinctada fucata (designated as PoMIF). The full-length of PoMIF was 1544 bp and consisted of a 5'-untranslated region (UTR) of 45 bp, a 3'-UTR of 1139 bp with a polyadenylation signal (AATAAA) at 12 nucleotides upstream of the poly (A) tail. The open reading frame (ORF) of PoMIF was 360 bp which encoded a polypeptide of 120 amino acids with an estimated molecular mass of 13.3 kDa and a predicted pI of 6.1. SMART analysis showed that PoMIF contained the catalytic-sites P² and K³³ for tautomerase activity, a motif C⁵⁷GSV⁶⁰ for oxidoreductase activity and a MIF family signature D⁵⁵PCGSVEVYSIGALG⁶⁹. Homology analysis revealed that the PoMIF shared 40.3-65.5% similarity and 26.9-45.0% identity to other known MIF sequences. PoMIF mRNA was constitutively expressed in seven selected tissues of healthy pearl oysters, with the highest expression level in digestive gland. Eight hours after P. fucata was injected with Vibrio alginolyticus, the expression of PoMIF mRNA was significantly up-regulated in digestive gland, gills, hemocytes and intestine. The cDNA fragment encoding mature protein of PoMIF was subcloned to expression vector pRSET and transformed into Escherichia coli BL21 (DE3). The recombinant PoMIF (rPoMIF) was expressed and purified under optimized conditions. Function analysis showed that rPoMIF had oxidoreductase activity and could utilize dithiothreitol (DTT) as reductant to reduce insulin.
Insights
The pearl oyster Pinctada fucata possesses a Macrophage Migration Inhibitory Factor (MIF) gene, PoMIF, crucial for innate immunity. PoMIF expression increases upon bacterial infection, indicating its role in oyster immune response.
Area of Science:
- Marine Biology
- Immunology
- Molecular Biology
Background:
- Macrophage Migration Inhibitory Factor (MIF) is a key cytokine regulating innate immunity.
- Understanding immune system components in invertebrates like pearl oysters is vital for aquaculture and disease resistance.
Purpose of the Study:
- To identify and characterize the Macrophage Migration Inhibitory Factor (MIF) cDNA from the pearl oyster Pinctada fucata (PoMIF).
- To investigate the expression patterns of PoMIF in response to bacterial challenge.
- To analyze the functional enzymatic activity of the recombinant PoMIF protein.
Main Methods:
- cDNA cloning and sequencing of PoMIF.
- Bioinformatic analysis of PoMIF sequence and protein structure.
- Quantitative real-time PCR (qRT-PCR) to analyze PoMIF mRNA expression in different tissues and after Vibrio alginolyticus infection.
- Recombinant expression and purification of PoMIF in E. coli.
- Enzymatic activity assays using insulin and dithiothreitol (DTT).
Main Results:
- The full-length PoMIF cDNA was characterized, encoding a 120-amino acid polypeptide with conserved MIF functional motifs.
- PoMIF mRNA was constitutively expressed in various pearl oyster tissues, with highest levels in the digestive gland.
- PoMIF expression was significantly upregulated in response to Vibrio alginolyticus infection.
- Recombinant PoMIF (rPoMIF) exhibited oxidoreductase activity, capable of reducing insulin.
Conclusions:
- PoMIF is a functional MIF cytokine in pearl oysters with conserved enzymatic activities.
- PoMIF plays a significant role in the innate immune response of Pinctada fucata against bacterial pathogens.
- This study provides insights into the molecular mechanisms of immunity in pearl oysters.
Related Concept Videos
01:25Immune Surveillance by NK Cells and Phagocytes
Natural Killer Cells: The Fast Responders
NK cells are large granular lymphocytes found in the blood and lymphatic system. These...
01:31Regulation of the Unfolded Protein Response