title: Pf-Sp8/9, a novel member of the specificity protein family in Pinctada fucata, potentially participates in biomineralization.
abstract: Specificity protein (Sp) belong to a transcription factor family that contains nine subgroups with essential functions in development, including skeletogenesis, tooth development, neural tube closure, and limb formation. In molluscs, functions of the Sp protein family members have not been reported in detail. In this study, we report the first Sp protein-encoding gene in Pinctada fucata. We named the translated protein Pf-Sp8/9, based on the phylogenetic development tree constructed using Sp protein sequences from six model organisms, which showed that it was a Sp8/9 homolog. Alignment of the Pf-Sp8/9 sequence with the amino acid sequences of related proteins showed that Pf-Sp8/9 had conserved domains, including three DNA-binding motifs. The tissue distribution showed that while Pf-Sp8/9 mRNA expression was detected in all tested tissues, it was particularly high in the mantle. The luciferase reporter assay results showed that Pf-Sp8/9 had the ability to activate the transcription of a number of matrix proteins. The expression pattern of Pf-Sp8/9 during P. fucata pearl sac development was similar to that of some genes that encode matrix proteins, suggesting Pf-Sp8/9 may be involved in mantle-related physiological activities and biomineralization.
authors.affiliation: Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, China.
authors.forename: Xiangnan
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xiang
authors.affiliation: Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liang
authors.affiliation: Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Protein Science Laboratory of the Ministry of Education, Tsinghua University, Beijing 100084, China. Electronic address: lpxie@mail.tsinghua.edu.cn.
authors.forename: Liping
authors.initials: L
authors.lastname: Xie
authors.affiliation: Institute of Marine Biotechnology, Collaborative Innovation Center of Deep Sea Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China; Protein Science Laboratory of the Ministry of Education, Tsinghua University, Beijing 100084, China. Electronic address: rqzhang@mail.tsinghua.edu.cn.
authors.forename: Rongqing
authors.initials: R
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002113:Calcification, Physiologic; D016326:Extracellular Matrix Proteins / Q000235:genetics; D010802:Phylogeny; D049911:Pinctada / Q000737:chemistry* / Q000378:metabolism; D016415:Sequence Alignment; D051703:Sp Transcription Factors / Q000235:genetics / Q000502:physiology*; D015533:Transcriptional Activation
chemical_list: D016326:Extracellular Matrix Proteins; D051703:Sp Transcription Factors
keywords: Gene expression; Mantle; Pearl sac development; Pinctada fucata; Specificity protein