A tuftelin-interacting protein (TIP39) localizes to the apical secretory pole of mouse ameloblasts
A tuftelin-interacting protein (TIP39) localizes to the apical secretory pole of mouse ameloblasts
复制标题
DOI：
10.1074/jbc.m000118200
复制
发表时间：
2000-07-21
影响因子：
4.8
通讯作者：
Snead, ML
中科院分区：
文献类型：
--
作者：
Paine, CT;Paine, ML;Snead, ML
牙釉质生物矿化是一个复杂的过程，涉及细胞外基质蛋白之间的相互作用。为了鉴定与tuftelin相互作用的蛋白质，一个潜在的成核剂的釉质微晶，酵母双杂交系统应用于小鼠牙齿表达文库和tuftelin-interacting蛋白（TIP）的分离进行进一步表征。制备了抗TIP 39蛋白的两种重组变体的多克隆抗体，两种抗体均鉴定出在牙齿器官中的主要蛋白产物，其分子量为39 kDa，该蛋白被称为TIP 39，北方分析显示TIP 39信使RNA在多个器官中存在，其模式类似于tuftelin信使RNA。用原位杂交技术检测了1日龄小鼠下颌骨中分泌型成釉细胞和成牙本质细胞中的TIP 39 RNA。TIP 39和tuftelin在体外培养的成釉细胞样细胞中的免疫定位结果表明，这两种蛋白质共定位。在发育中的牙齿器官中，TIP 39和tuftelin免疫定位于分泌型成釉细胞的顶端（Tomes'prostheses）和新分泌的细胞外釉基质。TIP 39氨基酸序列似乎高度保守，与酵母和灵长类等不同物种中的蛋白质具有相似性。现有的序列数据和本文报道的发现表明TIP 39在细胞外蛋白的分泌途径中的作用。
Enamel biomineralization is a complex process that involves interactions between extracellular matrix proteins. To identify proteins interacting with tuftelin, a potential nucleator of enamel crystallites, the yeast two-hybrid system was applied to a mouse tooth expression library and a tuftelin-interacting protein (TIP) was isolated for further characterization. Polyclonal antibodies were prepared against two recombinant variants of this protein, Both antibodies identified a major protein product in tooth organs at 39 kDa, and this protein has been called TIP39, Northern analysis showed TIP39 messenger RNA in multiple organs, a pattern similar to that of tuftelin messenger RNA. In situ hybridization of mandibles of 1-day-old mice detected TIP39 RNA in secretory ameloblasts and odontoblasts, Immunolocalization of TIP39 and tuftelin in cultured ameloblast-like cells showed that these two proteins colocalize, Within the developing tooth organ, TIP39 and tuftelin immunolocalized to the apical pole of secretory ameloblasts (Tomes' processes) and to the newly secreted extracellular enamel matrix. TIP39 amino acid sequence appears to be highly conserved with similarities to proteins in species as diverse as yeast and primates. Available sequence data and the findings reported here suggest a role for TIP39 in the secretory pathway of extracellular proteins.