Bio-sintering processes in hexactinellid sponges: Fusion of bio-silica in giant basal spicules from Monorhaphis chuni☆
| Autor: | Werner E.G. Müller, Matthias Wiens, Alexandra Boreiko, Joachim Bill, Xiaohong Wang, Anatoli Krasko, Ute Schlossmacher, Zaklina Burghard, Heinz C. Schröder |
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| Rok vydání: | 2009 |
| Předmět: |
Fusion
Spicule biology Hexactinellid Molecular Sequence Data Animal Structures Anatomy Blotting Northern Silicon Dioxide biology.organism_classification Porifera Sponge Lamella (surface anatomy) Sponge spicule Structural Biology Spectrometry Mass Matrix-Assisted Laser Desorption-Ionization Complementary DNA Microscopy Electron Scanning Biophysics Animals Lamellar structure |
| Zdroj: | Journal of Structural Biology. 168:548-561 |
| ISSN: | 1047-8477 |
| DOI: | 10.1016/j.jsb.2009.08.003 |
| Popis: | The two sponge classes, Hexactinellida and Demospongiae, comprise a skeleton that is composed of siliceous skeletal elements (spicules). Spicule growth proceeds by appositional layering of lamellae that consist of silica nanoparticles, which are synthesized via the sponge-specific enzyme silicatein. While in demosponges during maturation the lamellae consolidate to a solid rod, the lamellar organization of hexactinellid spicules largely persists. However, the innermost lamellae, near the spicule core, can also fuse to a solid axial cylinder. Similar to the fusion of siliceous nanoparticles and lamella, in several hexactinellid species individual spicules unify during sintering-like processes. Here, we study the different stages of a process that we termed bio-sintering, within the giant basal spicule (GBS) of Monorhaphis chuni. During this study, a major GBS protein component (27 kDa) was isolated and analyzed by MALDI-TOF-MS. The sequences were used to isolate and clone the encoding cDNA via degenerate primer PCR. Bioinformatic analyses revealed a significant sequence homology to silicatein. In addition, the native GBS protein was able to mediate bio-silica synthesis in vitro. We conclude that the syntheses of bio-silica in M. chuni, and the subsequent fusion of nanoparticles to lamellae, and finally to spicules, are enzymatically-driven by a silicatein-like protein. In addition, evidence is now presented that in hexactinellids those fusions involve sintering-like processes. |
| Databáze: | OpenAIRE |
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