Search results for "Sponge"

Interaction of the retinoic acid signaling pathway with spicule formation in the marine sponge Suberites domuncula through activation of bone morphog…

2011

Abstract Background The formation of the spicules in siliceous sponges involves the formation of cylinder-like structures in the extraspicular space, composed of the enzyme silicatein and the calcium-dependent lectin. Scope of review Molecular cloning of the cDNAs (carotene dioxygenase, retinal dehydrogenase, and BMB-1 [bone morphogenic protein-1]) from the demosponge Suberites domuncula was performed. These tools were used to understand the retinoid metabolism in the animal by qRT-PCR, immunoblotting and TEM. Major conclusions We demonstrate that silintaphin-2, a silicatein-interacting protein, is processed from a longer-sized 15-kDa precursor to a truncated, shorter-sized 13 kDa calcium-b…

Evidence for a symbiosis between bacteria of the genus Rhodobacter and the marine sponge Halichondria panicea  : harbor also for putatively toxic bac…

1998

Halichondria panicea (Pallas) is a marine sponge, abundantly occurring in the Adriatic sea, North sea and Baltic sea. It was the aim of the present study to investigate if this sponge species harbors bacteria. Cross sections through H. panicea were taken and inspected by electron microscopy. The micrographs showed that this sponge species is colonized by bacteria in its mesohyl compartment. To identify the bacteria, polymerase chain reaction (PCR) analysis of the 16S rRNA gene segment, typical for bacteria, was performed. DNA was isolated from sponge material that had been collected near Rovinj (Adriatic Sea), Helgoland (North Sea), and Kiel (Baltic Sea) and was amplified with bacterial pri…

The complete set of ribosomal proteins from the marine sponge Suberites domuncula

2005

The siliceous marine sponge Suberites domuncula is a member of the most ancient and simplest extant phylum of multicellular animals-Porifera, which have branched off first from the common ancestor of all Metazoa. We have determined primary structures of 79 ribosomal proteins (r-proteins) from S. domuncula: 32 proteins from the small ribosomal subunit and 47 proteins from the large ribosomal subunit. Only L39 and L41 polypeptides (51 and 25 residues long in rat, respectively) are missing. The sponge S. domuncula is, after nematode Caenorhabditis elegans and insect Drosophila melanogaster the third representative of invertebrates with known amino acid sequences of all r-proteins. The comparis…

Isolation of the silicatein-α interactor silintaphin-2 by a novel solid-phase pull-down assay.

2011

The skeleton of siliceous sponges consists of amorphous biogenous silica (biosilica). Biosilica formation is driven enzymatically by means of silicatein(s). During this unique process of enzymatic polycondensation, skeletal elements (spicules) that enfold a central proteinaceous structure (axial filament), mainly comprising silicatein, are formed. However, only the concerted action of silicatein and other proteins can explain the genetically controlled diversity of spicular morphotypes, from simple rods with pointed ends to intricate structures with up to six rays. With the scaffold protein silintaphin-1, a first silicatein interactor that facilitates the formation of the axial filament and…

Morphology of Sponge Spicules: Silicatein a Structural Protein for Bio-Silica Formation

2010

Most forms of multicellular life have developed a calcium-based skeleton, while only a few specialized organisms complement their body plan with silica, such as sponges (phylum Porifera). However, the way in which sponges synthesize their silica is exceptional. They use an enzyme, silicatein, for the polymerization/polycondensation of silica, and thereby form their highly resistant and stabile massive siliceous skeletal elements (spicules). During this biomineralization process (i.e., biosilicification), hydrated amorphous silica is deposited within highly specialized sponge cells, ultimately resulting in structures that range in size from micrometers to meters. This peculiar phenomenon has…

The role of the silicatein-alpha interactor silintaphin-1 in biomimetic biomineralization.

2008

Biosilicification in sponges is initiated by formation of proteinaceous filaments, predominantly consisting of silicateins. Silicateins enzymatically catalyze condensation of silica nanospheres, resulting in symmetric skeletal elements (spicules). In order to create tailored biosilica structures in biomimetic approaches it is mandatory to elucidate proteins that are fundamental for the assembly of filaments. Silintaphin-1 is a core component of modularized filaments and also part of a spicule-enfolding layer. It bears no resemblance to other proteins, except for the presence of an interaction domain that is fundamental for its function as scaffold/template. In the presence of silicatein sil…

Cover Picture: NanoSIMS: Insights into the Organization of the Proteinaceous Scaffold within Hexactinellid Sponge Spicules (ChemBioChem 8/2010)

2010

NanoSIMS: insights into the organization of the proteinaceous scaffold within Hexactinellid sponge spicules.

2010

The giant basal spicules (GBS) from Monorhaphis chuni (Porifera [sponges], Hexactinellida) represent the largest biosilica structures on Earth and can reach lengths of 300 cm (diameter of 1.1 cm). The amorphous silica of the inorganic matrix is formed enzymatically by silicatein. During this process, the enzyme remains trapped inside the lamellar-organized spicules. In order to localize the organic silicatein scaffold, the inside of a lamella has been analyzed by nano-secondary ion mass spectrometry (NanoSIMS). It is shown that the GBSs are composed of around 245 concentrically arranged individual siliceous lamellae. These surround an internal siliceous axial cylinder. The lamellae adjacent…

A synthetic biology approach for the fabrication of functional (fluorescent magnetic) bioorganic–inorganic hybrid materials in sponge primmorphs

2020

During evolution, sponges (Porifera) have honed the genetic toolbox and biosynthetic mechanisms for the fabrication of siliceous skeletal components (spicules). Spicules carry a protein scaffold embedded within biogenic silica (biosilica) and feature an amazing range of optical, structural, and mechanical properties. Thus, it is tempting to explore the low-energy synthetic pathways of spiculogenesis for the fabrication of innovative hybrid materials. In this synthetic biology approach, the uptake of multifunctional nonbiogenic nanoparticles (fluorescent, superparamagnetic) by spicule-forming cells of bioreactor-cultivated sponge primmorphs provides access to spiculogenesis. The ingested nan…

Scopolamine Derivatives as Potential Pharmaceuticals with Calixarene-CyclodextrineNanosponges as Drug Carriers

2017

Tropane alkaloids are molecules with a strong biological activity, which are mainly produced by the members offamily Solanaceae, but also found inother plant families (Convolvulaceae, Brasicaceae, Erythroxylaceae andEuphorbiaceae).1 More than 20 active pharmaceutical substances containingthetropane moiety have been industrially produced and applied as mydriatics, antiemetics, antispasmodics, anesthetics and bronchodilators.Nearly all of them are based on the Scopolamine structure.2 In recent years, several researchers aimed their work to the use of supramolecular systems for the inclusion of organic species, such as complex systems based on cyclodextrines or calixarenes.3They have attracted…