Simmer J P
University of Texas School of Dentistry, Health Science Center at San Antonio, Department of Pediatric Dentistry 78284-7888, USA.
Connect Tissue Res. 1995;32(1-4):131-6. doi: 10.3109/03008209509013715.
Amelogenins comprise as much as 90% of the protein in the developing enamel matrix. Separating amelogenins by gel electrophoresis reveals a complex of polypeptides with apparent mobilities ranging from low molecular weight species on up to 28,000 Daltons. A major objective of our research is determine the extent to which alternative RNA splicing contributes to this heterogeneity. We have cloned seven alternatively spliced mouse amelogenin mRNAs. The predicted translation products of these messages are 194, 180, 156, 141, 74, 59, and 44 amino acids in length. The 194 residue amelogenin is the only mouse amelogenin to include a polypeptide segment encoded by exon 4, which has a deduced amino acid sequence of KSHSQAINTDRTAL. Antibodies were raised against synthetic exon 4 encoded polypeptides and used to immunostain histologic tooth sections. These data indicate that alternatively spliced amelogenin mRNAs are translated into protein and secreted into the enamel matrix.
釉原蛋白占发育中的釉质基质中蛋白质的90%之多。通过凝胶电泳分离釉原蛋白可揭示出一组复杂的多肽，其表观迁移率范围从低分子量种类直至28,000道尔顿。我们研究的一个主要目标是确定可变RNA剪接在多大程度上导致了这种异质性。我们已经克隆了7种可变剪接的小鼠釉原蛋白mRNA。这些信使RNA的预测翻译产物长度分别为194、180、156、141、74、59和44个氨基酸。194个残基的釉原蛋白是唯一包含由外显子4编码的多肽片段的小鼠釉原蛋白，其推导的氨基酸序列为KSHSQAINTDRTAL。针对合成的外显子4编码多肽制备了抗体，并用于对组织学牙齿切片进行免疫染色。这些数据表明，可变剪接的釉原蛋白mRNA被翻译成蛋白质并分泌到釉质基质中。
