A novel rat dentin mRNA coding only for dentin sialoprotein.
A novel rat dentin mRNA coding only for dentin sialoprotein.
复制标题
一种仅编码牙本质唾液蛋白的新型大鼠牙本质 mRNA。
DOI：
10.1034/j.1600-0722.2001.00093.x
复制
发表时间：
2001
影响因子：
1.9
通讯作者：
Li,X
中科院分区：
文献类型：
--
作者：
Ritchie,HH;Li,X
牙本质涎蛋白（DSP）是存在于矿化牙本质基质中的主要糖蛋白，主要由年轻和成熟的成牙本质细胞表达。DSP编码区的突变与牙本质发生相关，表明DSP在牙齿形成中的重要性。先前的研究已经确定了多种mRNA转录在牙本质中编码DSP和磷酸化蛋白（PPs）。使用逆转录酶-聚合酶链反应（RT-PCR）来表征这些mRNA转录本，我们已经鉴定出编码DSP而不是PP的cDNA。该cDNA编码具有324个氨基酸的蛋白质，其中303个氨基酸与公开的大鼠DSP序列相同。然而，随后的21个氨基酸是该cDNA所特有的。基于编码序列，预测核心蛋白的pI=4.24，净电荷为−34，含有4个潜在的N-糖基化位点和6个潜在的酪蛋白激酶磷酸化位点。使用RNA保护测定证实了相应的mRNA存在于第5天的磨牙牙胚中。因此，这些数据，确定了一种新的转录本在大鼠牙胚，代码只为DSP（指定为DSPII）。
Dentin sialoprotein (DSP) is a major glycoprotein present in the mineralized dentin matrix that is expressed mainly by young and mature odontoblasts. Mutations in the DSP coding regions are linked to Dentinogenesis imperfecta I and II, indicating the importance of DSP in tooth formation. Previous studies have identified multiple mRNA transcripts in dentin that code for both DSP and phosphophoryns (PPs). Using reverse transcriptase‐polymerase chain reaction (RT‐PCR) to characterize these mRNA transcripts, we have identified a cDNA that codes for DSP, but not PP. This cDNA codes for a protein with 324 amino acids, 303 amino acids being identical to the published rat DSP sequence. However, the subsequent 21 amino acids are unique to this cDNA. Based on the coding sequence, the core protein is predicted to have a pI=4.24, a net charge of −34, and to contain four potential N‐glycosylation sites and six potential sites for phosphorylation by casein kinase. That the corresponding mRNA was present in day 5 molar tooth germs was confirmed using RNA protection assays. These data, therefore, identify a novel transcript in rat tooth germs that codes only for DSP (designated as DSPII).