Yuan Guohua, Wang Yinghua, Gluhak-Heinrich Jelica, Yang Guobin, Chen Lei, Li Tong, Wu Li-An, Chen Zhi, MacDougall Mary, Chen Shuo
Department of Pediatric Dentistry, The University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA.
Cell Biol Int. 2009 Aug;33(8):816-29. doi: 10.1016/j.cellbi.2009.05.001. Epub 2009 May 18.
Dentin sialophosphoprotein (DSPP) consists of dentin sialoprotein (DSP) and dentin phosphoprotein (DPP). DSPP is highly expressed in mineralized tissues. However, recent studies have shown that DSPP is also expressed in several active metabolic ductal epithelial tissues and exists in a variety of sequences. We have investigated DSPP expression in various mouse tissues using RT-PCR, in situ hybridization and immunohistochemical analyses. To identify DSPP gene polymorphisms, we screened a mouse tooth cDNA library as well as isolated and characterized DSPP variations. Our results show that DSPP is predominantly expressed in teeth and moderately in bone tissues. We also have characterized a full-length DSPP cDNA clone with an open-reading frame of 940 codons and this polyadenylation signal. Compared to previously reported mouse DSPP cDNAs, 13 sequence variations were identified, including 8 non-synonymous single nucleotide polymorphisms and an in-frame indel (8 amino acids) at DPP domain of the mouse DSPP. These 8 amino acids are rich in aspartic acid and serine residues. Northern blot assay showed a prominent band at 4.4kb. RT-PCR demonstrated that this mouse DSPP gene was dominantly expressed in teeth. The predicted secondary structure of DPP domain of this DSPP showed differences from the previously published mouse DPPs, implying that they play different roles during tooth development and formation.
牙本质涎磷蛋白（DSPP）由牙本质涎蛋白（DSP）和牙本质磷蛋白（DPP）组成。DSPP在矿化组织中高度表达。然而，最近的研究表明，DSPP也在几种活跃代谢的导管上皮组织中表达，并且存在多种序列形式。我们使用逆转录聚合酶链反应（RT-PCR）、原位杂交和免疫组织化学分析研究了DSPP在各种小鼠组织中的表达情况。为了鉴定DSPP基因多态性，我们筛选了小鼠牙齿cDNA文库，并分离和鉴定了DSPP变异体。我们的结果表明，DSPP主要在牙齿中表达，在骨组织中中度表达。我们还鉴定了一个全长DSPP cDNA克隆，其开放阅读框为940个密码子，并具有该多聚腺苷酸化信号。与先前报道的小鼠DSPP cDNA相比，鉴定出13个序列变异，包括8个非同义单核苷酸多态性以及小鼠DSPP的DPP结构域中的一个框内插入缺失（8个氨基酸）。这8个氨基酸富含天冬氨酸和丝氨酸残基。Northern印迹分析显示在4.4kb处有一条明显的条带。RT-PCR表明该小鼠DSPP基因在牙齿中占主导性表达。该DSPP的DPP结构域的预测二级结构与先前发表的小鼠DPPs不同，这意味着它们在牙齿发育和形成过程中发挥不同的作用。
