cePKU的特性分析：cePKU作用於線蟲DNA複製的控制

Abstract

遺傳訊息穩定的增殖必須仰賴生物體整個基因庫在細胞週期中一次又一次成功地複製。DNA複製許可系統（DNA replication licensing system）負責防止DNA在該次細胞週期中重複複製。因此，複製許可（replication licensing）對於細胞週期的進行是相當重要。我最近確認了一個基因cepku，可能作用於防止DNA的重複複製。我們的初步結果顯示cepku(RNAi)突變株會在早期胚胎發育過程中死亡，而且造成DNA含量的增加和異常漲大的細胞核性狀。cePKU的表現受細胞週期所調控，cePKU在有絲分裂末期開始表現，歷經G1期、S期、G2期、有絲分裂的前期持續表現。在有絲分裂的中期和後期，cePKU會受APC的調節而被分解。本篇報告主要討論cePKU的特性分析，推論cePKU可能是複製許可系統的負面調控因數（negative regulator），期望有助於我們對DNA複製許可系統的瞭解。

The maintenance of eukaryotic genome integrity requires the complete and accurate duplication of the entire genome once in every cell cycle. The events are monitored by the DNA replication licensing system which is responsible for preventing DNA re-replication in one cell cycle. Accordingly, replication licensing is very important for cell cycle progression. I have recently identified a gene, named cepku, that might prevent DNA re-replication. My preliminary results reveal that cepku (RNAi) mutants are arrested during early embryonic development and cause the phenotype of abnormally large nuclei and the increase of DNA content. cePKU is a cell-cycle- regulated kinase, which is degraded via anaphase promoting complex (APC) pathway during mitotic phase of the cell cycle. I propose that cePKU negatively regulates DNA re-replication and that cePKU destruction during metaphase and anaphase permits replication in proceeding cell cycle.