Watanabe T, Murakami K, Nakayama K
Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
FEBS Lett. 1993 Apr 12;320(3):215-8. doi: 10.1016/0014-5793(93)80589-m.
We have recently shown that the Arg/Lys-X-Lys/Arg-Arg or Arg/Lys-X-X-X-Lys/Arg-Arg sequence serves as a signal for cleavage of precursor proteins within the constitutive secretory pathway, and this cleavage is catalyzed by furin, a mammalian homolog of the yeast Kex2 protease. In this study, we further examined sequence requirements for the constitutive precursor cleavage. Based on the data concerning cleavage efficiencies of various prorenin mutants with amino acid substitution(s) around the native cleavage site expressed in CHO cells, we revised the sequence rules that govern the constitutive cleavage as follows: (i) the Arg residue at position -1 is essential; (ii) in addition to the Arg at position -1, at least two out of the three basic residues at positions -2, -4, and -6 are required for efficient cleavage (the presence of all the three basic residues results in most efficient cleavage); (iii) at position +1, a hydrophobic aliphatic amino acid is not suitable.
我们最近发现，精氨酸/赖氨酸-X-赖氨酸/精氨酸-精氨酸或精氨酸/赖氨酸-X-X-X-赖氨酸/精氨酸-精氨酸序列作为组成型分泌途径中前体蛋白切割的信号，这种切割由弗林蛋白酶催化，它是酵母Kex2蛋白酶的哺乳动物同源物。在本研究中，我们进一步研究了组成型前体切割的序列要求。基于在CHO细胞中表达的各种在天然切割位点周围具有氨基酸取代的肾素原突变体的切割效率数据，我们将控制组成型切割的序列规则修订如下：(i)-1位的精氨酸残基是必需的；(ii)除了-1位的精氨酸外，-2、-4和-6位的三个碱性残基中至少有两个对于有效切割是必需的（三个碱性残基都存在导致最有效的切割）；(iii)+1位的疏水性脂肪族氨基酸不合适。
