果蠅DEAD-box蛋白質Rs1的研究

Study of the Drosophila DEAD-box protein Rs1

邱若甄(Ruo-Chen Chiou)

指導教授 ： 黃敏郎

國立中正大學/理學院/生命科學系分子生物研究所/碩士(2014年)

摘要

Dead-box RNA helicase這類的蛋白質在各個物種上都具有高度的保留性，它在細胞中RNA的新陳代謝過程扮演了許多重要的生理角色，例如:轉錄、剪切、核糖體合成、運輸及轉譯等。在酵母菌中稱作Drs1的蛋白質已經被報導是參與在核糖體合成。然而，目前Drs1在高等生物的同源蛋白的功能仍是未知的。在我們的研究中，首先藉由complementation test方式發現帶有突變點的果蠅株EMS1和44B5-8這個區間有部分染色體缺失的果蠅株及Rs1 locus中帶有插入P-element的mutants Rs1K09514 和Rs1K09513交配都會trans-lethal，因此找到了Rs1突變株-Rs1EMS1。Rs1是Drs1的同源蛋白且屬於Dead-box RNA helicase family並有高度保留性，但其功能是未知的。做Mosaic clone analysis發現Rs1EMS1 and Rs1K09514 mutant clone 和旁邊的野生型clone比會消失或來得較小。但是在mutant clones內沒有細胞凋亡且不會影響整個eye discs中細胞增生或分化的能力。有趣的是，我們發現Rs1就像其他的核糖體蛋白一樣，有可能參與在細胞競爭當中。藉由序列分析的方法發現Rs1EMS1果蠅在Rs1基因序列中沒有找到任何的突變點。因此接下來，藉著利用P-element excision的方式讓P-element跳走，來獲得一個新的突變株-Rs150。而在我們的研究除了找到Rs1可能參與在細胞競爭外，也可藉著我們所得到的Rs1 mutants來進一步去探討Rs1的功能。

關鍵字

細胞競爭

並列摘要

Dead-box RNA helicase families are highly conserved in many species and have many essential physiological roles in cellular RNA metabolism including transcription, splicing, ribosome biogenesis, nucleocytoplasmic transport and translation. The yeast Dead-box RNA helicase, deficiency of ribosomal subunits (Drs1), is involved in ribosome biogenesis. However, the detail functions of the Drs1 orthologues in higher organisms are unknown. In our study, the data of complementation tests showed that the EMS line one (EMS1) was non-complement to the deficiencies on the cytological interval 44B5-8 and trans-lethal with the Rs1K09514 and Rs1K09513, which bears the P-element inserted at the Rs1 locus, suggesting that Rs1 mutant line-Rs1EMS1 was found. Rs1 is the orthologue of Drs1 and belongs to Dead-box RNA helicase family, but its detail functions are unknown. The mosaic clone analysis indicated that the clones of Rs1 mutants are missing or their size are much smaller than surrounding wild-type clones. However, none apoptosis signal was detected in Rs1 mutant clones and the cell proliferation or differentiation didn’t affect in eye discs. Interestingly, we found that Rs1 like other ribosomal proteins, might participate in cell competition. The sequence analysis of Rs1EMS1 showed no point mutations in Rs1 coding sequences. Therefore, we generated another Rs1 mutant-Rs150 by imprecise excision of P-element in Rs1K09513. So we found that Rs1 may involve in cell competition and mutants we got can be used to further explore Rs1 functions.

並列關鍵字

Dead-box protein

參考文獻

Baillon, L., and K. Basler. 2014. Reflections on cell competition: Growth,

Blair, S.S. 2003. Genetic mosaic techniques for studying Drosophila development.

Development. 130:5065-5072.

the expression of a large set of genes functioning in ribosome biogenesis and protein

Caruthers, J.M., and D.B. McKay. 2002. Helicase structure and mechanism.