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Shaked SA, Abehsera S, Ziegler A, Bentov S, Manor R, Weil S, Ohana E, Eichler J, Aflalo ED, Sagi A. A transporter that allows phosphate ions to control the polymorph of exoskeletal calcium carbonate biomineralization. Acta Biomater 2024; 178:221-232. [PMID: 38428510 DOI: 10.1016/j.actbio.2024.02.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 02/19/2024] [Accepted: 02/21/2024] [Indexed: 03/03/2024]
Abstract
The SLC20A2 transporter supplies phosphate ions (Pi) for diverse biological functions in vertebrates, yet has not been studied in crustaceans. Unlike vertebrates, whose skeletons are mineralized mainly by calcium phosphate, only minute amounts of Pi are found in the CaCO3-mineralized exoskeletons of invertebrates. In this study, a crustacean SLC20A2 transporter was discovered and Pi transport to exoskeletal elements was studied with respect to the role of Pi in invertebrate exoskeleton biomineralization, revealing an evolutionarily conserved mechanism for Pi transport in both vertebrates and invertebrates. Freshwater crayfish, including the study animal Cherax quadricarinatus, require repeated molt cycles for their growth. During the molt cycle, crayfish form transient exoskeletal mineral storage organs named gastroliths, which mostly contain amorphous calcium carbonate (ACC), an unstable polymorph long-thought to be stabilized by Pi. RNA interference experiments via CqSLC20A2 dsRNA injections reduced Pi content in C. quadricarinatus gastroliths, resulting in increased calcium carbonate (CaCO3) crystallinity and grain size. The discovery of a SLC20A2 transporter in crustaceans and the demonstration that knocking down its mRNA reduced Pi content in exoskeletal elements offers the first direct proof of a long-hypothesized mechanism by which Pi affects CaCO3 biomineralization in the crustacean exoskeleton. This research thus demonstrated the distinct role of Pi as an amorphous mineral polymorph stabilizer in vivo, suggesting further avenues for amorphous biomaterial studies. STATEMENT OF SIGNIFICANCE: • Crustaceans exoskeletons are hardened mainly by CaCO3, with Pi in minute amounts • Pi was hypothesized to stabilize exoskeletal amorphous mineral forms in vivo • For the first time, transport protein for Pi was discovered in crayfish • Transport knock-down resulted in exoskeletal CaCO3 crystallization and reduced Pi.
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Affiliation(s)
- Shai A Shaked
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Shai Abehsera
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Andreas Ziegler
- Central Facility for Electron Microscopy, University of Ulm, Albert-Einstein-Allee 11, 89069 Ulm, Germany
| | - Shmuel Bentov
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Rivka Manor
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Simy Weil
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Ehud Ohana
- Department of Clinical Biochemistry and Pharmacology, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Jerry Eichler
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
| | - Eliahu D Aflalo
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; Department of Life Sciences, Achva Academic College, 79804, Israel
| | - Amir Sagi
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel; The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel.
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Zhang X, Xia Z, Liu X, Li J. The novel matrix protein hic7 of hyriopsis cumingii participates in the formation of the shell and pearl. Comp Biochem Physiol B Biochem Mol Biol 2021; 256:110640. [PMID: 34182125 DOI: 10.1016/j.cbpb.2021.110640] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/16/2021] [Accepted: 06/22/2021] [Indexed: 10/21/2022]
Abstract
Shell matrix proteins have important roles in the biomineralization of shells. In this study, we isolated and identified a novel shell matrix protein gene, hic7, from the mussel Hyriopsis cumingii. The cDNA of hic7 was 459 bp long, including a 240-bp open reading frame. It encoded a 79 amino acid-long protein, with amino acids 1-19 constituting the signal peptide. The resulting hic7 is rich in cysteine (16.5%). After removing the signal peptide, the molecular weight was 8.85 kDa and the theoretical isoelectric point was 6.34, indicating that hic7 is a weakly acidic shell matrix protein. Hic7 is mainly expressed in the mantle tissue of H. cumingii. In situ hybridization showed hic7 signals at the edge and dorsal region of the mantle outer fold, indicating that it is related to the formation of the prismatic and nacreous layer of the shell. RNA interference indicated that when hic7 was inhibited by 80%, the crystal morphology of the prism and nacre layers of the shell were irregular and disordered. In addition, the expression of hic7 during the early development of the pearl sac indicated that it has an important role in the transformation of calcium carbonate crystals from a disordered to an orderly deposition pattern. These results suggest that matrix protein hic7 take part in constructing the framework of crystal nucleation and regulating the calcium carbonate crystal morphology of the nacreous and prismatic layers of shells and pearls.
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Affiliation(s)
- Xin Zhang
- Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China
| | - Zhonghui Xia
- Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China
| | - Xiaojun Liu
- Department of Biotechnology and Biomedicine, Yangtze Delta Region Institute of Tsinghua University, Zhejiang 314000, China.
| | - Jiale Li
- Key Laboratory of Freshwater Aquatic Genetic Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China; National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, Shanghai Ocean University, Shanghai 201306, China.
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