Department of Molecular Neurobiology, Graduate School of Life Sciences, Tohoku University, Aoba-ku, Sendai, Japan.
Dev Growth Differ. 2012 Feb;54(2):167-76. doi: 10.1111/j.1440-169X.2011.01315.x. Epub 2011 Dec 12.
Protogenin (PRTG) is a transmembrane protein of immunoglobulin superfamily, which has multiple roles in embryogenesis as a receptor or an adhesion molecule. In this study, we present sequential proteolytic cleavage of PRTG. The cleavage first occurs at the extracellular domain, then at the interface of the transmembrane and the intracellular domain by γ-secretase, which results in the release of the intracellular domain of PRTG (PRTG-ICD). PRTG-ICD contains putative nuclear localization signal (NLS) at its N-terminal, and translocates to the nucleus in cultured cells and in the neuroepithelial cells of chick embryos. We propose that the PRTG-ICD is cleaved by γ-secretase and translocates to the nucleus, which is potentially implicated in signaling for neural differentiation and in cell adhesion mediated by PRTG.
原朊素（PRTG）是免疫球蛋白超家族的跨膜蛋白，在胚胎发生过程中作为受体或黏附分子具有多种功能。在本研究中，我们提出了 PRTG 的连续蛋白水解切割。切割首先发生在细胞外结构域，然后由 γ-分泌酶在跨膜和细胞内结构域的界面处进行，导致 PRTG 的细胞内结构域（PRTG-ICD）释放。PRTG-ICD 在其 N 端含有推定的核定位信号（NLS），并在培养细胞和鸡胚神经上皮细胞中转位到细胞核。我们提出 PRTG-ICD 被 γ-分泌酶切割并转位到细胞核中，这可能与神经分化的信号转导以及 PRTG 介导的细胞黏附有关。
