Silica transport in the demosponge Suberites domuncula: fluorescence emission analysis using the PDMPO probe and cloning of a potential transporter.

Silicon is, besides oxygen, the most abundant element on earth. Only two taxa use this element as a major constituent of their skeleton, namely sponges (phylum Porifera) and unicellular diatoms. Results from combined cytobiological and molecularbiological techniques suggest that, in the demosponge Suberites domuncula, silicic acid is taken up by a transporter. Incubation of cells with the fluorescent silica tracer PDMPO [2-(4-pyridyl)-5-[[4-(2-dimethylaminoethylaminocarbamoyl)methoxy]phenyl]-oxazole] showed a response to silicic acid by an increase in fluorescence; this process is temperature-dependent and can be blocked by DIDS (4,4-di-isothiocyanatostilbene-2,2-disulphonic acid). The putative NBC (Na+/HCO3-) transporter was identified, cloned and analysed. The deduced protein comprises all signatures characteristic of those molecules, and phylogenetic analysis also classifies it to the NBC transporter family. This cDNA was used to demonstrate that the expression of the gene is strongly up-regulated after treatment of cells with silicic acid. In situ hybridization demonstrated that the expression of the sponge transporter occurs in those cells that are located adjacent to the spicules (the skeletal element of the animal) or in areas in which spicule formation occurs. We conclude that this transporter is involved in silica uptake and have therefore termed it the NBCSA [Na+/HCO3-[Si(OH)4]] co-transporter.

[1]  H. Schröder,et al.  Differentiation capacity of epithelial cells in the sponge Suberites domuncula , 2004, Cell and Tissue Research.

[2]  I. Nefkens,et al.  Polarity factor ‘Frizzled’ in the demosponge Suberites domuncula: identification, expression and localization of the receptor in the epithelium/pinacoderm 1 , 2003, FEBS letters.

[3]  S. Leys.  Comparative study of spiculogenesis in demosponge and hexactinellid larvae , 2003, Microscopy research and technique.

[4]  F. Sandford.  Physical and chemical analysis of the siliceous skeletons in six sponges of two groups (demospongiae and hexactinellida) , 2003, Microscopy research and technique.

[5]  Xavier Turon,et al.  Siliceous spicules and skeleton frameworks in sponges: Origin, diversity, ultrastructural patterns, and biological functions , 2003, Microscopy research and technique.

[6]  D. Morse,et al.  Molecular biology of demosponge axial filaments and their roles in biosilicification , 2003, Microscopy research and technique.

[7]  W. Boron,et al.  Cloning of a Na+-driven Cl/HCO3 exchanger from squid giant fiber lobe. , 2003, American journal of physiology. Cell physiology.

[8]  S. Sudek,et al.  Expression of one sponge Iroquois homeobox gene in primmorphs from Suberites domuncula during canal formation , 2003, Evolution & development.

[9]  M. Brzezinski,et al.  A novel fluorescent silica tracer for biological silicification studies. , 2001, Chemistry & biology.

[10]  M. Romero,et al.  Cloning and Characterization of a Na+-driven Anion Exchanger (NDAE1) , 2000, The Journal of Biological Chemistry.

[11]  H. Schröder,et al.  Expression of silicatein and collagen genes in the marine sponge Suberites domuncula is controlled by silicate and myotrophin. , 2000, European journal of biochemistry.

[12]  M. Úriz,et al.  Silica deposition in Demosponges: spiculogenesis in Crambe crambe , 2000, Cell and Tissue Research.

[13]  M. Brzezinski,et al.  THE CHEMICAL FORM OF DISSOLVED SI TAKEN UP BY MARINE DIATOMS , 1999 .

[14]  M. Maldonado,et al.  Decline in Mesozoic reef-building sponges explained by silicon limitation , 1999, Nature.

[15]  R. Haugland,et al.  A novel acidotropic pH indicator and its potential application in labeling acidic organelles of live cells. , 1999, Chemistry & biology.

[16]  M. Maldonado,et al.  Sexual propagation by sponge fragments , 1999, Nature.

[17]  W. Müller.  Establishment of a primary cell culture from a sponge: primmorphs from Suberites domuncula , 1999 .

[18]  W. Müller,et al.  Origin of the integrin-mediated signal transduction. Functional studies with cell cultures from the sponge Suberites domuncula. , 1999, European journal of biochemistry.

[19]  G. Stucky,et al.  Silicatein filaments and subunits from a marine sponge direct the polymerization of silica and silicones in vitro. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[20]  M. Hildebrand,et al.  Characterization of a silicon transporter gene family in Cylindrotheca fusiformis: sequences, expression analysis, and identification of homologs in other diatoms , 1998, Molecular and General Genetics MGG.

[21]  G. Stucky,et al.  Silicatein α: Cathepsin L-like protein in sponge biosilica , 1998 .

[22]  W. Müller,et al.  Early evolution of metazoan serine/threonine and tyrosine kinases: identification of selected kinases in marine sponges. , 1997, Molecular biology and evolution.

[23]  D. Barthel,et al.  Silica uptake of the marine sponge Halichondria panicea in Kiel Bight , 1997 .

[24]  G. Shields,et al.  Ediacarian sponge spicule clusters from southwestern Mongolia and the origins of the Cambrian fauna , 1997 .

[25]  John E. Coligan,et al.  Current Protocols in Protein Science , 1996 .

[26]  M. Cohen,et al.  K(+)- and HCO3(-)-dependent acid-base transport in squid giant axons II. Base influx , 1995, The Journal of general physiology.

[27]  S. Pelech.  Networking with protein kinases , 1993, Current Biology.

[28]  R. Reithmeier.  The erythrocyte anion transporter (band 3) , 1993 .

[29]  M. Kennish,et al.  Practical Handbook of Marine Science , 1988 .

[30]  Werner Müller,et al.  Specific phosphorylation of proteins in pore complex‐laminae from the sponge Geodia cydonium by the homologous aggregation factor and phorbol ester. Role of protein kinase C in the phosphorylation of DNA topoisomerase II. , 1987, The EMBO journal.

[31]  D. M. Nelson,et al.  SILICON UPTAKE BY ALGAE WITH NO KNOWN Si REQUIREMENT. II. STRONG pH DEPENDENCE OF UPTAKE KINETIC PARAMETERS IN PHAEODACTYLUM TRICORNUTUM (BACILLARIOPHYCEAE) 1 , 1985 .

[32]  T. Simpson,et al.  The Cell Biology of Sponges , 1984, Springer New York.

[33]  B. Volcani,et al.  Sodium-dependent silicate transport in the apochlorotic marine diatom Nitzschia alba. , 1980, Proceedings of the National Academy of Sciences of the United States of America.

[34]  C. Wilkinson,et al.  Ultrastructure of siliceous spicules and microsclerocytes in the marine sponge Neofibularia irata N. SP. , 1980, Journal of morphology.

[35]  R. Thomas,et al.  The role of bicarbonate, chloride and sodium ions in the regulation of intracellular pH in snail neurones , 1977, The Journal of physiology.

[36]  R. E. Shore.  AXIAL FILAMENT OF SILICIOUS SPONGE SPICULES, ITS ORGANIC COMPONENTS AND SYNTHESIS. , 1972, The Biological bulletin.

[37]  M. Jewell.  An Ecological Study of the Fresh‐Water Sponges of Northeastern Wisconsin , 1935 .

[38]  Teresa Adell,et al.  Bauplan of urmetazoa: basis for genetic complexity of metazoa. , 2004, International review of cytology.

[39]  Mario De Stefano,et al.  The phylogeny of the diatoms. , 2003, Progress in molecular and subcellular biology.

[40]  M. Úriz,et al.  Silica deposition in demosponges. , 2003, Progress in molecular and subcellular biology.

[41]  R. Wetherbee,et al.  Components and control of silicification in diatoms. , 2003, Progress in molecular and subcellular biology.

[42]  W. Müller,et al.  Silicase, an enzyme which degrades biogenous amorphous silica: contribution to the metabolism of silica deposition in the demosponge Suberites domuncula. , 2003, Progress in molecular and subcellular biology.

[43]  W. Müller,et al.  Iron induces proliferation and morphogenesis in primmorphs from the marine sponge Suberites domuncula. , 2002, DNA and cell biology.

[44]  M. Romero,et al.  Electrogenic Na+/HCO3- cotransporters: cloning and physiology. , 1999, Annual review of physiology.

[45]  H. Cingolani,et al.  An electrogenic sodium-bicarbonate cotransport in the regulation of myocardial intracellular pH. , 1995, Journal of molecular and cellular cardiology.

[46]  Jane A. Langdale,et al.  In situ Hybridization , 1994 .

[47]  R. Kopito.  Molecular biology of the anion exchanger gene family. , 1990, International review of cytology.

[48]  R. Garrone,et al.  The Cell Biology of Sponges, Springer Verlag, New York, 662 p., 221 fig. , 1985 .