title: Common genetic denominators for Ca++-based skeleton in Metazoa: role of osteoclast-stimulating factor and of carbonic anhydrase in a calcareous sponge.
abstract: Calcium-based matrices serve predominantly as inorganic, hard skeletal systems in Metazoa from calcareous sponges [phylum Porifera; class Calcarea] to proto- and deuterostomian multicellular animals. The calcareous sponges form their skeletal elements, the spicules, from amorphous calcium carbonate (ACC). Treatment of spicules from Sycon raphanus with sodium hypochlorite (NaOCl) results in the disintegration of the ACC in those skeletal elements. Until now a distinct protein/enzyme involved in ACC metabolism could not been identified in those animals. We applied the technique of phage display combinatorial libraries to identify oligopeptides that bind to NaOCl-treated spicules: those oligopeptides allowed us to detect proteins that bind to those spicules. Two molecules have been identified, the (putative) enzyme carbonic anhydrase and the (putative) osteoclast-stimulating factor (OSTF), that are involved in the catabolism of ACC. The complete cDNAs were isolated and the recombinant proteins were prepared to raise antibodies. In turn, immunofluorescence staining of tissue slices and qPCR analyses have been performed. The data show that sponges, cultivated under standard condition (10 mM CaCl(2)) show low levels of transcripts/proteins for carbonic anhydrase or OSTF, compared to those animals that had been cultivated under Ca(2+)-depletion condition (1 mM CaCl(2)). Our data identify with the carbonic anhydrase and the OSTF the first two molecules which remain conserved in cells, potentially involved in Ca-based skeletal dissolution, from sponges (sclerocytes) to human (osteoclast).
authors.affiliation: ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany. wmueller@uni-mainz.de
authors.forename: Werner E G
authors.initials: WE
authors.lastname: Müller
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.forename: Vlad A
authors.initials: VA
authors.lastname: Grebenjuk
authors.forename: Michael
authors.initials: M
authors.lastname: Korzhev
authors.forename: Matthias
authors.initials: M
authors.lastname: Wiens
authors.forename: Ute
authors.initials: U
authors.lastname: Schlossmacher
authors.forename: Heinz C
authors.initials: HC
authors.lastname: Schröder
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002119:Calcium Carbonate / Q000378:metabolism; D002122:Calcium Chloride / Q000378:metabolism; D002256:Carbonic Anhydrases / Q000235:genetics* / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000235:genetics / Q000378:metabolism; D010455:Peptides / Q000235:genetics* / Q000378:metabolism*; D011161:Porifera / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; D009842:Oligopeptides; D010455:Peptides; D011994:Recombinant Proteins; C408994:osteoclast stimulating factor; D002256:Carbonic Anhydrases; D002119:Calcium Carbonate; D002122:Calcium Chloride; D002118:Calcium