Differential complementation of a Neurospora crassa Galpha(i) mutation using mammalian Galpha protein genes.
Differential complementation of a Neurospora crassa Galpha(i) mutation using mammalian Galpha protein genes.
复制标题
使用哺乳动物 Galpha 蛋白基因对粗糙脉孢菌 Galpha(i) 突变进行差异互补。
DOI：
10.1007/pl00008687
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Borkovich,KA
中科院分区：
文献类型：
--
作者：
Yang,Q;Bieszke,JA;Borkovich,KA
Heterotrimeric (αβγ) G proteins interact with sensory receptors to transduce signals to downstream effectors in eukaryotes. We previously reported that GNA-1 fromNeurospora crassais a microbial member of the Gαifamily found in higher organisms. Deletion ofgna-1leads to female sterility, slower growth rates on normal and hyperosmotic solid medium, and increased resistance to heat and oxidative stress. In this study we compare mammalian genes for proteins of the Gαisubfamily (Gαi, Gαo, Gαtand Gαz), and Gαs(which is not a member of the Gαifamily) with theN. crassa gna-1gene with respect to their ability to complement Δgna-1phenotypes. Northern analysis detected full-length transcripts of all these genes, except that for Gαi, inN. crassatransformants. Measurements of pertussis toxin-catalyzed ADP-ribosylation and Western analysis showed that the GNA-1, Gαz, Gαoand Gαsproteins were present in the respective transformed strains. Strains in which the mammalian Gα protein could be detected were subjected to phenotypic testing. During the vegetative cycle, none of the mammalian Gα genes complemented the thermotolerance phenotype of Δgna-1. However, the three expressed mammalian Gα genes achieved at least partial complementation of the defects in vegetative apical extension rate. cAMP levels did not correlate with restoration of vegetative growth rate by the mammalian genes. During the sexual cycle, Gαowas the only mammalian Gα gene that rescued the defect in female fertility characteristic of Δgna-1strains. Alignment of GNA-1, Gαz, Gαoand Gαsprotein sequences revealed correlations between the observed complementation pattern and the degree of identity to GNA-1 in various functional motifs. The finding that Gαzgave the best restoration of vegetative growth but could not restore normal female fertility implies that GNA-1 regulates different pathways that are important for vegetative and sexual growth inN. crassa.
