Identification and functional characterization of a novel ferritin subunit from the tropical sea cucumber, Stichopus monotuberculatus.
Ferritin is one of the major non-harm iron storage proteins that found in most cell types of animals, plants and microorganisms. In this study, a ferritin subunit named StmFer was identified from the sea cucumber (Stichopus monotuberculatus) and characterized functionally. The full-length cDNA of StmFer is 1184 bp in size with a 5'-untranslated region (UTR) of 131 bp, a 3'-UTR of 531 bp and an open reading frame of 522 bp that encoding a protein of 173 amino acids with a deduced molecular weight of 19.95 kDa. StmFer possesses both the ferroxidase center of vertebrate ferritin heavy subunit and iron nucleation sites of vertebrate ferritin light subunit. For the gene structure, StmFer contains only three exons separated by two introns. Higher levels of mRNA expression were noticed in intestine and coelomocyte of S. monotuberculatus by northern blot analysis. In in vitro experiments performed in coelomocytes, transcriptional expression of StmFer showed the strongest response to polyriboinosinic polyribocytidylic acid [Poly (I:C)] (9.08 fold up-regulation), followed by lipopolysaccharides (LPS), ferrous chloride (FeCl2) and inactivated bacteria (Vibrio alginolyticus) (7.84, 7.41 and 4.90 fold up-regulation, respectively) after 3 h post-challenge. In addition, the anti-oxidation activity and iron binding capacity of recombinant ferritin protein were demonstrated in this study. As a whole, our study suggested that the ferritin from sea cucumber may play critical roles not only in the cellular and organismic iron homeostasis, but also in the innate immune defense.
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China. Electronic address: rosemary166@sina.com.
Chunhua
C
Ren
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China. Electronic address: chan1010@scsio.ac.cn.
Ting
T
Chen
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China. Electronic address: jiangxiao4367@126.com.
Xiao
X
Jiang
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China. Electronic address: yhwang@scsio.ac.cn.
Yanhong
Y
Wang
CAS Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB); Key Laboratory of Applied Marine Biology of Guangdong Province and Chinese Academy of Sciences (LAMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, PR China. Electronic address: hucq@scsio.ac.cn.
Chaoqun
C
Hu
D000818:Animals; D005293:Ferritins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D054884:Host-Pathogen Interactions; D021122:Protein Subunits; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012616:Sea Cucumbers / Q000378:metabolism*; D044149:Vibrio alginolyticus
D021122:Protein Subunits; D012333:RNA, Messenger; D005293:Ferritins
Anti-oxidation activity; Ferritin; Innate immune defense; Iron binding capacity; Stichopus monotuberculatus