title: Occurrence of a silicatein gene in glass sponges (Hexactinellida: Porifera).
abstract: Silicatein genes are involved in spicule formation in demosponges (Demospongiae: Porifera). However, numerous attempts to isolate silicatein genes from glass sponges (Hexactinellida: Porifera) resulted in a limited success. In the present investigation, we performed analysis of potential silicatein/cathepsin transcripts in three different species of glass sponges (Pheronema raphanus, Aulosaccus schulzei, and Bathydorus levis). In total, 472 clones of such transcripts have been analyzed. Most of them represent cathepsin transcripts and only three clones have been found to represent transcripts, which can be related to silicateins. Silicatein transcripts were identified in A. schulzei (Hexactinellida; Lyssacinosida; Rosselidae), and the corresponding gene was called AuSil-Hexa. Expression of AuSil-Hexa in A. schulzei was confirmed by real-time PCR. Comparative sequence analysis indicates high sequence identity of the A. schulzei silicatein with demosponge silicateins described previously. A phylogenetic analysis indicates that the AuSil-Hexa protein belongs to silicateins. However, the AuSil-Hexa protein contains a catalytic cysteine instead of the conventional serine.
authors.affiliation: Institute of Biology and Soil Science, Far East Branch of Russian Academy of Sciences, Vladivostok, Russia.
authors.forename: Galina N
authors.initials: GN
authors.lastname: Veremeichik
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Shkryl
authors.forename: Victor P
authors.initials: VP
authors.lastname: Bulgakov
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Shedko
authors.forename: Valery B
authors.initials: VB
authors.lastname: Kozhemyako
authors.forename: Svetlana N
authors.initials: SN
authors.lastname: Kovalchuk
authors.forename: Vladimir B
authors.initials: VB
authors.lastname: Krasokhin
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Zhuravlev
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Kulchin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D002403:Cathepsins / Q000235:genetics*; D002681:China; D003001:Cloning, Molecular; D019295:Computational Biology; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D020869:Gene Expression Profiling; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D010802:Phylogeny; D011161:Porifera / Q000235:genetics*; D011487:Protein Conformation; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; C112571:silicatein alpha; D002403:Cathepsins