Guichard Annabel, Srinivasan Shaila, Zimm Georgianna, Bier Ethan
Section of Cell and Developmental Biology, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0349, USA.
Proc Natl Acad Sci U S A. 2002 Mar 19;99(6):3752-7. doi: 10.1073/pnas.052028699.
The Drosophila epidermal growth factor receptor (EGF-R) controls many critical cell fate choices throughout development. Several proteins collaborate to promote localized EGF-R activation, such as Star and Rhomboid (Rho), which act sequentially to ensure the maturation and processing of inactive membrane-bound EGF ligands. To gain insights into the mechanisms underlying Rho and Star function, we developed a mutagenesis scheme to isolate novel overexpression activity (NOVA) alleles. In the case of rho, we isolated a dominant neomorphic allele, which interferes with Notch signaling, as well as a dominant-negative allele, which produces RNA interference-like flip-back transcripts that reduce endogenous rho expression. We also obtained dominant-negative and neomorphic Star mutations, which have phenotypes similar to those of rho NOVA alleles, as well as dominant-negative Egf-r alleles. The isolation of dominant alleles in several different genes suggests that NOVA mutagenesis should be widely applicable and emerge as an effective tool for generating dominant mutations in genes of unknown function.
果蝇表皮生长因子受体（EGF-R）在整个发育过程中控制着许多关键的细胞命运选择。几种蛋白质协同作用以促进局部EGF-R激活，例如Star和类菱形蛋白（Rho），它们依次发挥作用以确保无活性的膜结合EGF配体的成熟和加工。为了深入了解Rho和Star功能的潜在机制，我们开发了一种诱变方案来分离新型过表达活性（NOVA）等位基因。对于rho，我们分离出一个显性新等位基因，它干扰Notch信号传导，以及一个显性负等位基因，它产生类似RNA干扰的回翻转录本，降低内源性rho表达。我们还获得了显性负性和新的Star突变，其表型与rho NOVA等位基因相似，以及显性负性Egf-r等位基因。在几个不同基因中分离出显性等位基因表明，NOVA诱变应该具有广泛的适用性，并成为在功能未知基因中产生显性突变的有效工具。
