2014-08-012024-05-17https://scholars.lib.ntu.edu.tw/handle/123456789/688525摘要：核醣體是一個很大的複合體，需要經過多重、且複雜的步驟來完成一個核醣體的合成，是細胞內非常耗能的過程。合成從核仁開始，當合成到一定程度時，核醣體必須通過核膜上的核孔複合體(nuclear pore complex, NPC)，在細胞質完成最後熟成步驟，才能開始轉譯蛋白質。核醣體分子量很大，幾乎是NPC運輸的上限，而且rRNA帶負電，跟NPC通道中的疏水性蛋白會產生結合上的困難。因此，核醣體需要export receptors幫助其和nucleoporins (Nup)間的作用，來順利通過核孔複合體。到現在為止，酵母菌的大核醣體共有五個export receptors被發現: Crm1、Mex67/Mtr2、Arx1、Ecm1及Npl3。他們除了幫助出核，也幫助核醣體的合成過程，並更是調控的關鍵點。Rlp24是核醣體生合成的輔助蛋白，和Rpl24 (大核醣體蛋白24)的N端具有高度的相似性，是核醣體結合區塊；但Rlp24具有一個較長的C端區塊，將此端去除時，rlp24&#8710;C沒辦法從細胞質的60S核醣體上離開，重新進入核內來幫助下一輪的核醣體合成。在我們的初步實驗結果中，發現另一個C端具有突變的RLP24 突變株(rlp24CC)：當將rlp24CC放入野生株時，並沒有明顯的表徵，但放入nup120及arx1突變株中時，會造成嚴重的生長缺失，而且嚴重阻斷60S的出核過程。這顯示Rlp24的功能和核醣體的出核途徑有緊密的關聯性。在本篇研究的目的中，我們將探討Rlp24在核醣體出核所具有的角色及可能的調控機制。<br> Abstract: Ribosomes biogenesis is highly energy-consuming process in the cell. The synthesis starts from the nucleolus and matures at cytoplasm, where ribosomes carry out protein translation. Ribosomes are very large complexes and cannot pass through the nuclear pore complex (NPC) on their own. In addition, the function of export receptors is to help the ribosomal subunits out of the nucleus by assisting interaction between the ribosome and the NPC. Further, they are also function as transacting factors and regulation points in ribosome biogenesis. The object of this proposal is how Rlp24 will be necessary for ribosome export. In our preliminary data, when Rlp24 (ribosomal protein 24-like protein) containing C terminal domain mutations (rlp24CC) was introduced to cells deficient either at Nup120 (a nucleoporin) or at Arx1 (a ribosome export receptor), it severely impaired the growth and ribosome export. This observation suggests that a functional interaction between Rlp24 and ribosome export is need to be focus more. Rlp24 and the interaction partners, Nog1 and Mak11, are involved in cell signaling process. At present no attention was paid on Rlp24 at its role of ribosome export. In this proposal, we would like to address the functional role of Rlp24 in the export pathway of 60S subunits and its regulatory mechanism will be studied using the budding yeast Saccharomyces cerevisiae as a model system.核醣體核醣體生合成核孔複合體出核途徑Rlp24Ribosomeribosome biogenesisexportNuclear Pore ComplexRlp24