Apekin V, Goldberger G, Oppenheim F G, Paz M A
Laboratory of Human Biochemistry, Children's Hospital Corporation, Boston, Massachusetts.
J Dent Res. 1991 Feb;70(2):95-8. doi: 10.1177/00220345910700021801.
Xenopus laevis oocytes injected with poly (A+) RNA isolated from rat parotid and submandibular glands synthesize and secrete salivary proteins. Amylase was identified in the media of cultured oocytes injected with rat parotid mRNA by size and immunoprecipitation with anti-human amylase serum. Secretion of the salivary proteins was detectable in the medium eight h following the parotid mRNA injection and continued in a time-dependent fashion for up to 96 h. In contrast to rat parotid slices in culture, which demonstrate a regulated pathway of secretion highly responsive to the secretagogue isoproterenol, secretion of salivary proteins by oocytes did not respond to the stimulation by isoproterenol. Though parotid mRNA is presumed to contain the templates encoding the regulated pathway of secretion, reconstitution of this pathway of secretion in oocytes was not observed in our experiments. Since Xenopus laevis oocytes secrete constitutively significant amounts of proteins when injected with salivary gland mRNA, they are a useful biological system for the analysis of secretion, processing, and function of salivary proteins.
注射了从大鼠腮腺和颌下腺分离得到的多聚腺苷酸（poly (A+)）RNA的非洲爪蟾卵母细胞能够合成并分泌唾液蛋白。通过大小和用抗人淀粉酶血清进行免疫沉淀，在注射了大鼠腮腺mRNA的培养卵母细胞的培养基中鉴定出了淀粉酶。在注射腮腺mRNA后8小时，培养基中可检测到唾液蛋白的分泌，并以时间依赖的方式持续长达96小时。与培养中的大鼠腮腺切片不同，后者表现出对促分泌剂异丙肾上腺素高度敏感的调节性分泌途径，卵母细胞分泌唾液蛋白对异丙肾上腺素的刺激没有反应。尽管推测腮腺mRNA包含编码调节性分泌途径的模板，但在我们的实验中未观察到卵母细胞中该分泌途径的重建。由于非洲爪蟾卵母细胞在注射唾液腺mRNA时会组成性地分泌大量蛋白质，它们是用于分析唾液蛋白的分泌、加工和功能的有用生物系统。
