Search results for "Domu"

The sponge silicatein-interacting protein silintaphin-2 blocks calcite formation of calcareous sponge spicules at the vaterite stage

2013

Ca-carbonate, the inorganic matrix of the spicules from the calcareous sponges, is formed as the result of an enzyme-catalyzed reaction with the carbonic anhydrase [CA] as a decisive component. The growth and the morphology of the spicules are genetically controlled, and are taxon-specific. In the present study it is shown that the silicatein-interacting protein silintaphin-2 is present at the surface of the siliceous spicules of the demosponge Suberites domuncula and prevents the association of calcareous crystals synthesized in vitro to these skeletal elements. Silintaphin-2 comprises a Ca2+-binding domain that is formed by a 22 amino acid-long peptide, N-DDDSQGEIQSDMAEEEDDDNVD-C. This ve…

Species-Specific Aggregation Factor in Sponges

1978

An aggregation factor (AF) from the siliceous sponge Suberites domuncula has been isolated and purified by the following steps: Sepharose 2 B gel chromatography, sucrose gradient, Nonidet treatment, Sephadex G-100 gel chromatography and DEAE-Sephadex ion-exchange chromatography. By this procedure the AF was purified 1340-fold with a 63% yield nearly to homogeneity. The AF is originally associated with large particles, characterized by a sedimentation of 2200 S. These particles have been visualized electron microscopically; they are characterized by a filament-like shape of a length of 3400 A and a cross-sectional diameter of 230 A. The purified, low-molecular weight AF has a buoyant density…

Silicateins, the major biosilica forming enzymes present in demosponges: protein analysis and phylogenetic relationship.

2007

Silicateins are enzymes, which are restricted to sponges (phylum Porifera), that mediate the catalytic formation of biosilica from monomeric silicon compounds. The silicatein protein is compartmented in the sponges in the axial filaments which reside in the axial canals of the siliceous spicules. In the present study silicatein has been isolated from the freshwater sponge Lubomirskia baicalensis where it occurs in isoforms with sizes of 23 kDa, 24 kDa and 26 kDa. Since the larger protein is glycosylated we posit that it is a processed form of one of the smaller size forms. The silicatein isoforms are post-translationally modified by phosphorylation; at least four isoforms exist with pI's of…

Application of a MTT Assay for Screening Nutritional Factors in Growth Media of Primary Sponge Cell Culture

2004

Marine sponges (Porifera) are producers of the largest variety of bioactive compounds among benthic marine organisms. In vitro culture of marine sponge cells has been proposed for the sustainable production of these pharmacologically interesting compounds from marine sponges but with limited success. The development of a suitable growth medium is an essential prerequisite for sponge cells grown in vitro. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was adapted to screen for potential nutritional factors in formulating a growth medium for primary cell culture of Suberites domuncula. In 96-well plates, the effects of nutritional factors including glutamine, pyr…

The stem cell concept in sponges (Porifera): Metazoan traits.

2006

Sponges are considered the oldest living animal group and provide important insights into the earliest evolutionary processes in the Metazoa. This paper reviews the evidence that sponge stem cells have essential roles in cellular specialization, embryogenesis and Bauplan formation. Data indicate that sponge archaeocytes not only represent germ cells but also totipotent stem cells. Marker genes have been identified which are expressed in totipotent stem cells and gemmule cells. Furthermore, genes are described for the three main cell lineages in sponge, which share a common origin from archaeocytes and result in the differentiation of skeletal, epithelial, and contractile cells.

Molecular evolution of the metazoan extracellular matrix: cloning and expression of structural proteins from the demosponges Suberites domuncula and …

2000

One crucial event during evolution to multicellularity was the development of either direct cell–cell contact or indirect interaction via extracellular matrix (ECM) molecules. The identification of those polypeptides provides conclusive data on the phylogenetic relationship of metazoan phyla and helps us to understand the position of the Metazoa among the other kingdoms. Recently it became evident that the ECM of sponges is amazingly complex; it is composed of fibrous molecules, e.g., collagen, and their corresponding receptors, which are highly similar to those existing in other metazoan phyla. While these data already support the view of monophyly of Metazoa, additional studies are requir…

Zvaigžņotā Debess: 2000, Rudens (169)

2000

Contents: M.Zepe. Water Steam in the Venus Atmosphere ; B.Sala, L.Kondraševa. Use of Solar Energy ; A.Balklavs. Century Long Astrophysics ; Z.Alksne, A.Alksnis. Plenty of Extrasolar Planets ; Z.Alksne, A.Alksnis. Unexpected Discovery of Spiral Structure in a Dwarf Elliptical Galaxy ; A.Balklavs. Hunting for the Black Holes ; J.Jaunbergs. Private Enterprise on Mir ; T.Czarnik. Surviving Explosive Decompression ; M.Gills. Space Research 40 Years Ago – Chronicle ; M.Krastiņš. Impressions about Rose Center for the Earth and Space ; K.Bērziņš. On Friendly Terms with Cosmology: Basic Principles and Models of the Universe (continuation) ; V.Flerov, A.Cēbers, D.Docenko, V.Kaščejev. Latvia 24th Open…

Cloning and expression of the sponge longevity gene SDLAGL.

2000

Porifera show a characteristic Bauplan in spite of the fact that (almost) all cells are telomerase-positive and presumably provided with an unlimited potency for cell proliferation. One gene, SDLAGL, was identified in the marine sponge Suberites domuncula whose deduced polypeptide showed high sequence similarity to the longevity assurance genes from other Metazoa. While in single cells no transcripts of SDLAGL could be identified, high expression was seen after re-aggregation of single cells and in proliferating cells of primmorphs.

Cloning of sponge heat shock proteins: evolutionary relationships between the major kingdoms

2009

In the present study we have cloned from sponges (Porifera) those molecules which are involved in the protection of organisms against physiological and stress conditions; the inducible heat shock protein Mr 70,000, hsp70, from the marine sponge Geodia cydonium, its interacting hsp40, a DnaJ-like protein (from G. cydonium) and the constitutively expressed counterpart the glucose-regulated protein Mr 78,000, GRP78 from Suberites domuncula. Alignments of the sequences revealed that the deduced aa sequences of all sponge hsp's share high homology to other metazoan sequences, and are separated from related sequences from plants and fungi (hsp70, GRP78, DnaJ) as well as Bacteria (DnaK, the hsp70 …

La committenza gesuitica e la pittura a Palermo tra XVI e XVIII secolo

Il presente lavoro di ricerca mira ad approfondire e arricchire, mediante nuove acquisizioni, lo studio in merito alle opere pittoriche di committenza gesuitica custodite presso le fondazioni palermitane dell’Ordine: chiesa del Gesù a Casa Professa, Collegio Massimo dei Gesuiti, chiesa di San Stanislao Kostka e chiesa di San Francesco Saverio. A queste si aggiungono i dipinti di committenza della Compagnia trasferiti presso altre sedi. Ulteriore intento è quello di organizzare in maniera più organica la trattazione delle commissioni artistiche dell’Ordine a Palermo, che si presentava dispersiva e frammentaria. Tra i risultati più significativi si annovera il ritrovamento di un ciclo di affr…