title: Silicatein genes in spicule-forming and nonspicule-forming Pacific demosponges.
abstract: Silicatein genes are known to be involved in siliceous spicule formation in marine sponges. Proteins encoded by these genes, silicateins, were recently proposed for nanobiotechnological applications. We studied silicatein genes of marine sponges Latrunculia oparinae collected in the west Pacific region, shelf of Kuril Islands. Five silicatein genes, LoSilA1, LoSilA1a, LoSilA2, and LoSilA3 (silicatein-alpha group), LoSilB (silicatein-beta group), and one cathepsin gene, LoCath, were isolated from the sponge L. oparinae for the first time. The deduced amino acid sequence of L. oparinae silicateins showed high-sequence identity with silicateins described previously. LoCath contains the catalytic triad of amino acid residues Cys-His-Asn characteristic for cathepsins as well as motifs typical for silicateins. A phylogenetic analysis places LoCath between sponge silicateins-beta and L-cathepsins suggesting that the LoCath gene represents an intermediate form between silicatein and cathepsin genes. Additionally, we identified, for the first time, silicatein genes (AcSilA and AcSilB) in nonspicule-forming marine sponge, Acsmall a, Cyrillicnthodendrilla sp. The results suggest that silicateins could participate also in the function(s) unrelated to spiculogenesis.
authors.affiliation: Pacific Institute of Bioorganic Chemistry, Far East Branch of Russian Academy of Sciences, Vladivostok, Russia. kozhemyako@hotmail.com
authors.forename: Valeri B
authors.initials: VB
authors.lastname: Kozhemyako
authors.forename: Galina N
authors.initials: GN
authors.lastname: Veremeichik
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Shkryl
authors.forename: Svetlana N
authors.initials: SN
authors.lastname: Kovalchuk
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Krasokhin
authors.forename: Valeri A
authors.initials: VA
authors.lastname: Rasskazov
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Zhuravlev
authors.forename: Victor P
authors.initials: VP
authors.lastname: Bulgakov
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Kulchin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002403:Cathepsins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D010140:Pacific Ocean; D010802:Phylogeny; D011161:Porifera / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: C112571:silicatein alpha; D002403:Cathepsins