Watanabe T, Nakagawa T, Ikemizu J, Nagahama M, Murakami K, Nakayama K
Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
J Biol Chem. 1992 Apr 25;267(12):8270-4.
We have recently demonstrated that the Arg-X-Lys/Arg-Arg sequence is a signal for precursor cleavage catalyzed by furin, a mammalian homologue of the yeast precursor-processing endoprotease Kex2, within the constitutive secretory pathway. In this study, we further examined sequence requirements for the constitutive precursor cleavage by expression of various prorenin mutants with amino acid substitutions around the native Lys-Arg cleavage site in Chinese hamster ovary cells. The results delineate the following sequence rules that govern the constitutive precursor cleavage. (a) A basic residue (Lys or Arg) at the 4th (position -4) or 6th (position -6) residue upstream of the cleavage site besides basic residues at positions -1 and -2 is necessary. (b) At position -2, a Lys residue is more preferable than Arg. (c) At position -4, an Arg residue is more preferable than Lys. (d) At position 1, a hydrophobic aliphatic amino acid is not suitable.
我们最近证明，在组成型分泌途径中，Arg-X-Lys/Arg-Arg序列是由弗林蛋白酶（一种酵母前体加工内切蛋白酶Kex2的哺乳动物同源物）催化的前体切割信号。在本研究中，我们通过在中国仓鼠卵巢细胞中表达各种在天然Lys-Arg切割位点周围具有氨基酸取代的肾素原突变体，进一步研究了组成型前体切割的序列要求。结果描绘了以下控制组成型前体切割的序列规则。(a) 除了-1和-2位的碱性残基外，切割位点上游第4位（-4位）或第6位（-6位）的碱性残基（Lys或Arg）是必需的。(b) 在-2位，Lys残基比Arg更合适。(c) 在-4位，Arg残基比Lys更合适。(d) 在+1位，疏水性脂肪族氨基酸不合适。
