Hartman H, Wu M, Buchanan B B, Gerhart J C
Department of Plant Biology, University of California, Berkeley 94720.
Proc Natl Acad Sci U S A. 1993 Mar 15;90(6):2271-5. doi: 10.1073/pnas.90.6.2271.
A role for thioredoxin in metazoan DNA synthesis has been assessed by injecting rapidly dividing Xenopus eggs with purified heterologous thioredoxins, which might act as inhibitors if they were to replace resident thioredoxins in some but not all reaction steps. Of 10 tested proteins, spinach chloroplast thioredoxin m is the most potent inhibitor. Eggs cleave and produce cells lacking nuclei. DNA synthesis is severely reduced. Development arrests before gastrulation. In egg extracts, thioredoxin m inhibits incorporation of radioactive dCTP into DNA of sperm nuclei and M13 phage. Inhibition exceeds 90% when thioredoxin m and M13 DNA are preincubated together. The data support the interpretation that thioredoxins normally participate in initiation of metazoan DNA synthesis.
通过向快速分裂的非洲爪蟾卵中注射纯化的异源硫氧还蛋白，评估了硫氧还蛋白在多细胞动物DNA合成中的作用。如果这些异源硫氧还蛋白在某些而非所有反应步骤中取代了内源性硫氧还蛋白，它们可能会起到抑制剂的作用。在测试的10种蛋白质中，菠菜叶绿体硫氧还蛋白m是最有效的抑制剂。卵会分裂并产生无细胞核的细胞。DNA合成严重减少。发育在原肠胚形成前停止。在卵提取物中，硫氧还蛋白m抑制放射性dCTP掺入精子细胞核和M13噬菌体的DNA中。当硫氧还蛋白m与M13 DNA预孵育时，抑制率超过90%。这些数据支持了硫氧还蛋白通常参与多细胞动物DNA合成起始的解释。
