TBC-2 is required for embryonic yolk protein storage and larval survival during L1 diapause in Caenorhabditis elegans.
TBC-2 is required for embryonic yolk protein storage and larval survival during L1 diapause in Caenorhabditis elegans.
复制标题
DOI：
10.1371/journal.pone.0015662
复制
发表时间：
2010-12-28
期刊：
影响因子：
3.7
通讯作者：
Rocheleau CE
中科院分区：
文献类型：
--
作者：
Chotard L;Skorobogata O;Sylvain MA;Shrivastava S;Rocheleau CE
C.线虫第一阶段（L1）幼虫在没有食物的情况下孵化，停止发育并进入L1滞育，由此它们可以在饥饿中存活数周。在L1滞育的生存的生理和代谢要求知之甚少。然而，蛋黄，胆固醇结合/转运蛋白，已被建议作为能源。在此，我们证明了C. elegans TBC-2是一种RAB-5 GTP酶激活蛋白（GAP），参与早期到晚期内体的转换，对于胚胎发育过程中的卵黄蛋白储存和饥饿时L1的存活都很重要。我们发现，在胚胎发生过程中，蛋黄：：绿色荧光蛋白融合（YP 170：：GFP），消失得更快，tbc-2突变体胚胎相比，野生型对照胚胎。在tbc-2突变体中YP 170：：GFP的过早消失可能是由于溶酶体中的过早降解，因为我们发现YP 170：：GFP显示出与Lysotracker Red（酸性区室的标记物）的共定位增加。此外，YP 170：：GFP在tbc-2突变体中的消失需要RAB-7，一种内体向溶酶体运输的调节剂。虽然tbc-2在喂养的动物中不是必需的，但我们发现tbc-2突变体L1幼虫在没有食物的情况下孵化时存活率大大降低。我们发现，TBC-2突变幼虫是没有缺陷的维持L1滞育和突变体缺陷的蛋黄摄取，RME-1和RME-6，也强烈降低了L1的生存孵化时，在没有食物。我们的研究结果表明，TBC-2是所需的卵黄蛋白在胚胎发育过程中的存储和提供强相关的数据表明，卵黄构成了一个重要的能源，幼虫生存在L1滞育。
C. elegans first stage (L1) larvae hatched in the absence of food, arrest development and enter an L1 diapause, whereby they can survive starvation for several weeks. The physiological and metabolic requirements for survival during L1 diapause are poorly understood. However, yolk, a cholesterol binding/transport protein, has been suggested to serve as an energy source. Here, we demonstrate that C. elegans TBC-2, a RAB-5 GTPase Activating Protein (GAP) involved in early-to-late endosome transition, is important for yolk protein storage during embryogenesis and for L1 survival during starvation. We found during embryogenesis, that a yolk::green fluorescent protein fusion (YP170::GFP), disappeared much more quickly in tbc-2 mutant embryos as compared with wild-type control embryos. The premature disappearance of YP170::GFP in tbc-2 mutants is likely due to premature degradation in the lysosomes as we found that YP170::GFP showed increased colocalization with Lysotracker Red, a marker for acidic compartments. Furthermore, YP170::GFP disappearance in tbc-2 mutants required RAB-7, a regulator of endosome to lysosome trafficking. Although tbc-2 is not essential in fed animals, we discovered that tbc-2 mutant L1 larvae have strongly reduced survival when hatched in the absence of food. We show that tbc-2 mutant larvae are not defective in maintaining L1 diapause and that mutants defective in yolk uptake, rme-1 and rme-6, also had strongly reduced L1 survival when hatched in the absence of food. Our findings demonstrate that TBC-2 is required for yolk protein storage during embryonic development and provide strong correlative data indicating that yolk constitutes an important energy source for larval survival during L1 diapause.
登录
查看更多内容
影响因子：
1.5
作者：
Britton, C;Murray, L
通讯作者：
Murray, L
DOI：
10.1083/jcb.131.6.1435
发表时间：
1995-12
期刊：
The Journal of cell biology
影响因子：
--
作者：
Feng Y;Press B;Wandinger-Ness A
通讯作者：
Wandinger-Ness A
影响因子：
2.7
作者：
KIMBLE, J;SHARROCK, WJ
通讯作者：
SHARROCK, WJ
影响因子：
3.9
作者：
SPIETH, J;NETTLETON, M;BLUMENTHAL, T
通讯作者：
BLUMENTHAL, T
影响因子：
3.3
作者：
Matyash, V;Geier, C;Kurzchalia, TV
通讯作者：
Kurzchalia, TV