The complete family of genes encoding G proteins of Caenorhabditis elegans
The complete family of genes encoding G proteins of Caenorhabditis elegans
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DOI：
10.1038/7753
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发表时间：
1999-04-01
期刊：
影响因子：
30.8
通讯作者：
Plasterk, RHA
中科院分区：
文献类型：
--
作者：
Jansen, G;Thijssen, KL;Plasterk, RHA
秀丽隐杆线虫是第一个基因组序列已被确定的动物（1）。后序列遗传学的一个新的可能性是一次分析完整的基因家族。我们研究了异源三聚体G蛋白家族（2）。秀丽隐杆线虫有20个G α、2个G β和2个G γ基因。哺乳动物的4类G α基因G（i）/G（o）α、G（s）α、G（q）α和G（12）α各有1个同源物，并且有16个新的α基因。虽然保守的G α亚基在许多神经元和肌肉细胞中表达（3-7），但GFP融合表明14种新的G α基因几乎仅在秀丽隐杆线虫的化学感受神经元的一小部分中表达（8，9）。我们使用靶选择基因失活产生功能丧失等位基因（10，11）。没有一个两亲体表达的基因是生存所必需的，只有四个显示出任何可检测的表型（趋化性缺陷），这表明广泛的功能冗余。根据功能分析，编码G α蛋白的20个基因可以分为两组：编码影响肌肉活动的亚基的基因（G（i）/G（o）alpha G（s）alpha和G（q）的同源物;参考文献3-6），以及编码最可能参与感知的蛋白质的基因（14个新基因）。
Caenorhabditis elegans is the first animal whose genomic sequence has been determined(1). One of the new possibilities in post-sequence genetics is the analysis of complete gene families at once. We studied the family of heterotrimeric G proteins(2). C, elegans has 20 G alpha, 2 G beta and 2 G gamma genes. There is 1 homologue of each of the 4 mammalian classes of G alpha genes, G(i)/G(o)alpha, G(s)alpha, G(q)alpha and G(12)alpha, and there are 16 new alpha genes. Although the conserved G alpha subunits are expressed in many neurons and muscle cells(3-7), GFP fusions indicate that 14 new G alpha genes are expressed almost exclusively in a small subset of the chemosensory neurons of C, elegans(8,9). We generated loss-of-function alleles using target-selected gene inactivation(10,11). None of the amphid-expressed genes are essential for viability, and only four show any detectable phenotype (chemotaxis defects), suggesting extensive functional redundancy. On the basis of functional analysis, the 20 genes encoding G alpha proteins can be divided into two groups: those that encode subunits affecting muscle activity (homologues of G(i)/G(o)alpha G(s)alpha and G(q); refs 3-6), and those (14 new genes) that encode proteins most likely involved in perception.