Molecular cloning, mRNA expression and characterization of membrane-bound hemoglobin in oriental river prawn Macrobrachium nipponense.
Most hemoglobins are respiratory proteins and are ubiquitous in animals, bacteria, fungi, protists, and plants. In this study, we describe a membrane-bound hemoglobin in the oriental river prawn Macrobrachium nipponense (MnHb), which also expresses hemocyanin. MnHb cDNA was cloned using the rapid amplification of cDNA ends (RACE) approach, which afforded a 1201bp gene encoding a 193 amino acid polypeptide. Bioinformatic evaluation suggested MnHb is membrane anchored by N-myristoylation, and immunofluorescence confirmed its location in the membrane of chief cells in the gill. The effect of hypoxia on MnHb expression was investigated, and reverse transcription PCR (RT-PCR) and Western blotting showed that MnHb was expressed almost exclusively in the gill. Quantitative RT-PCR revealed a significant increase in expression after 6h of hypoxia, and levels peaked at 24h due to oxidative stress. Exposure of cultured prawns to the stress inducer H2O2 significantly up-regulated the expression of MnHb in a dose-dependent manner. MnHb may have a role in protecting cell membrane lipids from damage by reactive oxygen species.
['Sun|Shengming|S|', 'Xuan|Fujun|F|', 'Fu|Hongtuo|H|', 'Zhu|Jian|J|', 'Ge|Xianping|X|', 'Wu|Xugan|X|']
D000818:Animals D003001:Cloning, Molecular D018076:DNA, Complementary D005786:Gene Expression Regulation D005880:Gills D006454:Hemoglobins D000860:Hypoxia D008566:Membranes D018384:Oxidative Stress D033541:Palaemonidae D010802:Phylogeny D045483:Rivers
Membrane-bound hemoglobin Macrobrachium nipponense Gill Hypoxia Oxidative stress