Abstract
Genomic and transcriptomic studies have revealed a sophisticated and powerful apoptosis regulation network in oyster, highlighting its adaptation to sessile life in a highly stressful intertidal environment. However, the functional molecular basis of apoptosis remains largely unexplored in oysters. In this study, we focused on a representative apoptotic gene encoding voltage-dependent anion channel 2 (VDAC2), a porin that abounds at the mitochondrial outer membrane. This is the first report on the identification and characterization of a VDAC gene in the Pacific oyster, Crassostrea gigas (CgVDAC2). The full length of CgVDAC2 was 1,738 bp with an open reading frame of 843 bp that encoded a protein of 281 amino acids. A four-element eukaryotic porin signature motif, a conserved ATP binding motif, and a VKAKV-like sequence were identified in the predicted CgVDAC2. Expression pattern analysis in different tissues and developmental stages as well as upon infection by ostreid herpesvirus 1 revealed the energy supply-related and immunity-related expression of CgVDAC2. CgVDAC2 was co-localized with mitochondria when it was transiently transfected into HeLa cells. Overexpression of CgVDAC2 in HEK293T cells suppressed the UV irradiation-induced apoptosis by inhibiting the pro-apoptotic function of CgBak. RNA interference induced reduction in CgVDAC2 expression showed a promoted apoptosis level upon UV light irradiation in hemocytes. The yeast two-hybrid system and co-immunoprecipitation assay indicated a direct interaction between CgVDAC2 and the pro-apoptotic protein CgBak. This study revealed the function of VDAC2 in oyster and provided new insights into its involvement in apoptosis modulation and host defense in mollusks.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adaptation, Physiological
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Adaptive Immunity
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Amino Acid Motifs
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Amino Acid Sequence
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Animals
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Apoptosis / genetics
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Apoptosis / radiation effects
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Base Sequence
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Cloning, Molecular
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Gene Expression Regulation, Developmental
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HeLa Cells
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Hemocytes / radiation effects
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Herpesviridae
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Humans
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Mitochondrial Proteins / chemistry
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Mitochondrial Proteins / genetics
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Mitochondrial Proteins / isolation & purification
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Mitochondrial Proteins / physiology
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Molecular Sequence Data
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Open Reading Frames / genetics
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Organ Specificity
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Ostreidae / genetics
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Ostreidae / immunology
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Ostreidae / metabolism*
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Ostreidae / virology
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Protein Interaction Mapping
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RNA Interference
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Recombinant Fusion Proteins / metabolism
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Sequence Alignment
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Sequence Homology, Amino Acid
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Signal Transduction
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Transfection
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Two-Hybrid System Techniques
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Ultraviolet Rays
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Voltage-Dependent Anion Channel 2 / chemistry
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Voltage-Dependent Anion Channel 2 / genetics
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Voltage-Dependent Anion Channel 2 / isolation & purification
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Voltage-Dependent Anion Channel 2 / physiology*
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bcl-2 Homologous Antagonist-Killer Protein / metabolism
Substances
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Mitochondrial Proteins
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Recombinant Fusion Proteins
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Voltage-Dependent Anion Channel 2
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bcl-2 Homologous Antagonist-Killer Protein
Grants and funding
This research was supported by National Basic Research Program of China (973 Program, No.2010CB126402), the National Natural Science Foundation of China (31302219), the National High Technology Research and Development Program (863 program, 2012AA10A405), the Earmarked Fund for Modern Agro-industry Technology Research System (CARS-48) and Taishan Scholars Climbing Program of Shandong. All the funders had important roles in study design, data collection and analysis.