A genetic suppressor of two dominant temperature-sensitive lethal proteasome mutants of Drosophila melanogaster is itself a mutated proteasome subunit gene

作者：Neuburger Peter J; Saville Kenneth J; Zeng Jue; Smyth Kerrie Ann; Belote John M^*

来源：Genetics, 2006, 173(3): 1377-1387.

DOI：10.1534/genetics.106.057976

Two dominant temperature-sensitive (DTS) lethal mutants of Drosophila melanogaster are Pros26(1) and Pros beta 2(1), previously known as DTS5 and DTS7. Heterozygotes for either mutant die as pupae when raised at 29 degrees, but are normally viable and fertile at 25 degrees. Previous studies have identified these as missense mutations in the genes encoding the beta 6 and beta 2 subunits of the 20S proteasome, respectively. In an effort to isolate additional proteasome-related mutants a screen for dominant suppressors of Pros26(1) was carried out, resulting in the identification of Pros25(SuDTS) [originally called Su(DTS)], a missense mutation in the gene encoding the 20S proteasome alpha 2 subunit. Pros25(SuDTS) acts in a dominant manner to rescue both Pros26(1) and Pros beta 2(1) from their DTS lethal phenotypes. Using an in vivo protein degradation assay it was shown that this suppression occurs by counteracting the dominant-negative effect of the DTS mutant on proteasome activity. Pros25(SuDTS) is a recessive polyphasic lethal at ambient temperatures. The effects of these mutants on larval neuroblast mitosis were also examined. While Pros beta 2(1) shows a modest increase in the number of defective mitotic figures, there were no defects seen with the other two mutants, other than slightly reduced mitotic indexes.

• 出版日期2006-7