Abstract
摘要：在果蠅的卵母細胞中，oskar 信息核糖核酸的後端定位是胚胎腹部與生殖前驅細胞發育上很重要的程序。信息核糖核酸裁剪所需複合體，轉譯調控因子與其他蛋白質形成了指引oskar 信息核糖核酸往卵母細胞後端定位的核糖核酸複合體。我們首先確認果蠅去蓋頭酵素1，dDcp1，是oskar 信息核糖核酸在後端定位與裂解所需要的(附件1)。
我們的假說是只有包含信息核糖核酸裂解系統的osk核糖核酸複合體可以被送到其最後的目的地以保證oskar 信息核糖核酸在轉譯以後的正確裂解。在卵發育的第九期後，若沒有果蠅去蓋頭酵素1以及信息核糖核酸裂解系統在內， osk 核糖核酸複合體不能夠被正確的聚合以及被往後傳輸。
此計畫將以解開果蠅去蓋頭酵素1蛋白質的更詳細功能為主要目標。在卵發育早期的果蠅去蓋頭酵素1功能將被探討，這將協助我們回答果蠅去蓋頭酵素1是否一如其人類同源蛋白質SMIF也是TGF 訊息路徑的一個成員。以及我們將進一步探討果蠅去蓋頭酵素1如何與其他成員作用以調控oskar 信息核糖核酸得傳輸。 遺傳修飾者搜尋與酵母菌雙雜交搜尋與果蠅去蓋頭酵素1相互作用的因子將是一主要主題。我們亦將詢問
Abstract: Functional approach of
Drosophila decapping protein 1 and oskar mRNA localizaiton
In Drosophila, the posterior deposition of oskar (osk) mRNA in the oocyte is critical for pole cell and abdomen formation. Exon junction complex components, translational regulation factors and other proteins form the RNP complex necessary for directing osk mRNA to the posterior end of oocyte. We have first shown that Drosophila decapping protein 1, dDcp1, is essential for osk mRNA posterior deposition and degradation (Appendix 1).
We propose that only a complete osk mRNP complex, including the degradation machinery, can be sent to its final destination so as to ensure the proper degradation of osk mRNA after translation. After stage 9, without dDcp1 and the mRNA degradation system involved, the osk mRNP complex can not be assembled properly and transported posteriorly.
This project is aimed at to elucidate more about dDcp1 protein functions. The function of dDcp1 during early oogenesis will be approached. This will assist us in answering whether dDcp1 is a TGF signaling component as its human homologue SMIF does. And, we will further explore the mechanics how dDcp1 interacts with related components in regulating osk mRNA transportation. Genetic modifier screen and two hybrid screen for dDcp1 interaction factors will be our major theme. We will also ask two possible dDcp1 interaction candidates, Me31B and Pacman. Me31B as its yeast homolog Dhh1p may stimulates mRNA decapping and participate dDcp1 function. Pacman encodes the Drosophila Xrn1 5’-3’ exonuclease. By biochemical and genetic methods, these two candidates will be asked for their possible roles in osk mRNA posterior localization.
In this field, we first report that mRNA degradation system acts in osk mRNA posterior localization, which is expected to have strong impact in cell biology and RNA related studies. This grant project is designed to further elucidate the machinery behind and to maintain the lead in this study.
Keyword(s)
oskar 信息核糖核酸
RNA 定位
果蠅去蓋頭酵素1
TGF signaling
oskar mRNA
RNA localization
Drosophila decapping protein 1
TGFsignaling
