Department of Clinical Neuroscience, Huddinge Division of Neurology, Karolinska Institute, Huddinge University Hospital, 141 86 Huddinge, Sweden.
Invest New Drugs. 2010 Jun;28(3):242-50. doi: 10.1007/s10637-009-9238-4. Epub 2009 Mar 17.
By using mini-units of tissue and protease inhibitors in short term incubation (0-180 min), we studied the role of proteolysis for ongoing DNA replication in the developing rat cerebral cortex. The protease inhibitors TLCK, TPCK, PMSF, MG-132 and PSI markedly inhibited DNA synthesis. The inhibitory effects were concentration-dependent and of early onset (within 60 min). The most selective proteasome inhibitors lactacystin and clasto-lactacystin-beta-lactone as well as the calpain inhibitor I and II had no or minimal effects on DNA synthesis. Only high concentrations of calpain inhibitor I (>or= 250 microM) and calpain inhibitor II (>or= 500 microM) gave a DNA synthesis inhibition. These results suggest that (1) ongoing DNA replication is regulated by proteolysis and (2) the proteolytic pathways involved are neither the proteasome nor the calpains.
通过使用组织的微单位和短期孵育（0-180 分钟）中的蛋白酶抑制剂，我们研究了蛋白水解对于正在进行的 DNA 复制在发育中的大鼠大脑皮层中的作用。蛋白酶抑制剂 TLCK、TPCK、PMSF、MG-132 和 PSI 显著抑制 DNA 合成。抑制作用呈浓度依赖性并且发生得很早（在 60 分钟内）。最具选择性的蛋白酶体抑制剂乳胞素和 clasto-lactacystin-beta-内酯以及钙蛋白酶抑制剂 I 和 II 对 DNA 合成没有或几乎没有影响。只有高浓度的钙蛋白酶抑制剂 I（>或=250 microM）和钙蛋白酶抑制剂 II（>或=500 microM）才会抑制 DNA 合成。这些结果表明：（1）正在进行的 DNA 复制受蛋白水解的调节，（2）涉及的蛋白水解途径既不是蛋白酶体也不是钙蛋白酶。
