Facultative polypeptide translocation allows a single mRNA to encode the secreted and cytosolic forms of plasminogen activators inhibitor 2.
Facultative polypeptide translocation allows a single mRNA to encode the secreted and cytosolic forms of plasminogen activators inhibitor 2.
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兼性多肽易位允许单个 mRNA 编码纤溶酶原激活剂抑制剂 2 的分泌形式和胞质形式。
作者：
Dominique Belin;A. Wohlwend;Wolf;Egbert K. O. Kruithof;J. Vassalli
人和小鼠单核/巨噬细胞合成了两种形式的纤溶酶原激活物抑制物2(PAI-2)：一种积聚在胞浆中，另一种移位到内质网中，糖化并分泌。首先，通过Northern印迹杂交和核糖核酸酶保护检测到单一的PIA-2基因。其次，PAI-2基因的转导导致了两种形式的PAI-2的合成。最后，在有微粒体膜的情况下，体外翻译PAI-2的mRNA转录本产生了两种不同的PAI-2形式。胞液和分泌形式的PAI-2并不是由于使用了两个翻译起始点，因为它们的合成起始于同一个8月，在人类和小鼠基因之间保守的序列环境中。因此，一个多肽积累到两个拓扑不同的细胞隔间可以通过兼性易位实现。
Two forms of plasminogen activators inhibitor 2 (PAI‐2) are synthesized by human and murine monocytes/macrophages: one accumulates in the cytosol, while the other is translocated into the endoplasmic reticulum, glycosylated and secreted. We show here that a single mRNA encodes both forms of PAI‐2. Firstly, a single PIA‐2 mRNA was detected by Northern blot hybridization and by RNase protection. Secondly, transfection of a PAI‐2 cDNA led to the synthesis of both forms of PAI‐2. Finally, in vitro translation of an mRNA transcript of the PAI‐2 cDNA in the presence of microsomal membranes generated two topologically distinct forms of PAI‐2. The cytosolic and secreted forms of PAI‐2 do not result from the use of two translation start sites, since their synthesis initiates at the same AUG, in a sequence context that is conserved between the human and murine genes. Thus, the accumulation of one polypeptide into two topologically distinct cellular compartments can be achieved by facultative translocation.