Matefin, a Caenorhabditis elegans germ line-specific SUN-domain nuclear membrane protein, is essential for early embryonic and germ cell development
Matefin, a Caenorhabditis elegans germ line-specific SUN-domain nuclear membrane protein, is essential for early embryonic and germ cell development
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DOI：
10.1073/pnas.0307880101
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发表时间：
2004-05-04
影响因子：
11.1
通讯作者：
Gruenbaum, Y
中科院分区：
文献类型：
--
作者：
Fridkin, A;Mills, E;Gruenbaum, Y
秀丽隐杆线虫mtf-1编码matefin蛋白，该蛋白具有一个SUN结构域、一个卷曲螺旋区、一个抗erbB-2 IgG结构域和两个疏水区。我们发现，matefin是一种核膜蛋白，共定位在体内与Ce-核纤层蛋白，单核核纤层蛋白在线虫，并结合Ce-核纤层蛋白在体外，但不需要Ce-核纤层蛋白的本地化。Matefin在所有胚胎细胞中检测到，直到胚胎中期发生，此后仅在种系细胞中检测到。胚胎matefin是母体沉积的，并且matefin是已知的第一个具有生殖系限制表达的核膜蛋白。mtf-1缺失等位基因纯合子动物表明，马泰芬对生殖系成熟和存活至关重要。然而，matefin也是胚胎发生所必需的，因为mtf-1（RNAi）胚胎在大约300个细胞阶段死亡，核结构、DNA含量和染色质形态都有缺陷。在mes-3动物中下调matefin仅轻微增强胚胎致死率，而C. elegans，对mtf-1（RNAi）动物没有影响。因此，mtf-1介导了胚胎发生以及生殖系增殖或存活所需的先前未表征的途径。
Caenorhabditis elegans mtf-1 encodes matefin, which has a predicted SUN domain, a coiled-coil region, an anti-erbB-2 IgG domain, and two hydrophobic regions. We show that matefin is a nuclear membrane protein that colocalizes in vivo with Ce-lamin, the single nuclear lamin protein in C elegans, and binds Ce-lamin in vitro but does not require Ce-lamin for its localization. Matefin is detected in all embryonic cells until midembryogenesis and thereafter only in germ-line cells. Embryonic matefin is maternally deposited, and matefin is the first nuclear membrane protein known to have germ line-restricted expression. Animals homozygous for an mtf-1 deletion allele show that matefin is essential for germ line maturation and survival. However, matefin is also required for embryogenesis because mtf-1 (RNAi) embryos die around the approximate to300-cell stage with defects in nuclear structure, DNA content, and chromatin morphology. Down-regulating matefin in mes-3 animals only slightly enhances embryonic lethality, and elimination of UNC-84, the only other SUN-domain gene in C. elegans, has no affect on mtf-1 (RNAi) animals. Thus, mtf-1 mediates a previously uncharacterized pathway(s) required for embryogenesis as well as germ line proliferation or survival.