Filamin and phospholipase C-ε are required for calcium signaling in the Caenorhabditis elegans spermatheca.
Filamin and phospholipase C-ε are required for calcium signaling in the Caenorhabditis elegans spermatheca.
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DOI：
10.1371/journal.pgen.1003510
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发表时间：
2013-05
期刊：
影响因子：
4.5
通讯作者：
Cram EJ
中科院分区：
文献类型：
--
作者：
Kovacevic I;Orozco JM;Cram EJ
秀丽隐杆线虫精囊是一个储存精子的肌上皮管，当卵母细胞进入、受精和退出子宫时，它经历伸展和收缩的循环。FLN-1/丝蛋白（一种拉伸敏感结构和信号支架）和PLC-1/磷脂酶C-ε（一种产生第二信使IP3的酶）是胚胎在受精后正常退出所必需的。利用基因编码钙指示剂GCaMP，我们发现卵母细胞进入精囊后会引发一系列独特的ip3依赖性钙振荡，这些振荡通过间隙连接在组织中传播，并导致精囊收缩。卵母细胞进入触发的钙释放机制需要PLC-1，及时启动钙振荡需要FLN-1。INX-12是一种间隙连接亚基，负责协调钙离子在精囊内的传递。ITR-1/IP3R （IP3依赖性钙通道）的功能获得突变和LFE-2 （IP3信号的负调节因子）的功能缺失突变增加了钙的释放并抑制了丝蛋白缺乏动物的出口缺陷。我们进一步证明，由MEL-11/肌凝蛋白磷酸酶和NMY-1/非肌凝蛋白组成的调节盒是精子包膜协调收缩所必需的。综上所述，本研究回答了关于秀丽隐杆线虫精囊中钙信号动力学的长期问题，并表明FLN-1在响应卵母细胞进入以触发钙释放和精囊组织协调收缩时是需要的。在生物体发育和正常生理功能过程中，细胞感知、整合和响应各种线索或信号，包括生化和机械刺激。在这项研究中，我们使用秀丽隐杆线虫，一种小的透明蠕虫，研究丝蛋白（FLN-1），一种可能作为分子应变计的结构蛋白。秀丽隐杆线虫的精囊是一个可收缩的管，在正常功能下被拉伸，使其成为研究细胞如何对拉伸做出反应的理想候选者。卵母细胞被排入精囊，受精，然后被精囊的收缩推入子宫。精囊收缩的能力取决于肌醇1,4,5-三磷酸（IP3），这是一种由磷脂酶C （PLC-1）产生的信号分子，可触发细胞内钙的释放。在FLN-1或PLC-1突变的动物中，精囊细胞不能收缩。通过基因分析和钙敏感荧光蛋白，我们发现FLN-1与PLC-1一起调节IP3的产生、钙的释放和精囊的收缩。丝蛋白可以感知进入卵母细胞引起的拉伸并触发收缩。这些发现建立了丝蛋白和钙信号之间的联系，可能适用于其他系统中的类似信号通路。
The Caenorhabditis elegans spermatheca is a myoepithelial tube that stores sperm and undergoes cycles of stretching and constriction as oocytes enter, are fertilized, and exit into the uterus. FLN-1/filamin, a stretch-sensitive structural and signaling scaffold, and PLC-1/phospholipase C-ε, an enzyme that generates the second messenger IP3, are required for embryos to exit normally after fertilization. Using GCaMP, a genetically encoded calcium indicator, we show that entry of an oocyte into the spermatheca initiates a distinctive series of IP3-dependent calcium oscillations that propagate across the tissue via gap junctions and lead to constriction of the spermatheca. PLC-1 is required for the calcium release mechanism triggered by oocyte entry, and FLN-1 is required for timely initiation of the calcium oscillations. INX-12, a gap junction subunit, coordinates propagation of the calcium transients across the spermatheca. Gain-of-function mutations in ITR-1/IP3R, an IP3-dependent calcium channel, and loss-of-function mutations in LFE-2, a negative regulator of IP3 signaling, increase calcium release and suppress the exit defect in filamin-deficient animals. We further demonstrate that a regulatory cassette consisting of MEL-11/myosin phosphatase and NMY-1/non-muscle myosin is required for coordinated contraction of the spermatheca. In summary, this study answers long-standing questions concerning calcium signaling dynamics in the C. elegans spermatheca and suggests FLN-1 is needed in response to oocyte entry to trigger calcium release and coordinated contraction of the spermathecal tissue. During organism development and normal physiological function cells sense, integrate, and respond to a variety of cues or signals including biochemical and mechanical stimuli. In this study we used Caenorhabditis elegans, a small transparent worm, to study filamin (FLN-1), a structural protein that may act as a molecular strain gauge. The C. elegans spermatheca is a contractile tube that is stretched during normal function, making it an ideal candidate for study of how cells respond to stretch. Oocytes are ovulated into the spermatheca, fertilized, and then pushed into the uterus by constriction of the spermatheca. The ability of the spermatheca to constrict depends on inositol 1,4,5-triphosphate (IP3), a signaling molecule produced by the enzyme phospholipase C (PLC-1) that triggers calcium release within cells. In animals with mutated FLN-1 or PLC-1 the spermathecal cells fail to constrict. Using genetic analysis and a calcium-sensitive fluorescent protein, we show that FLN-1 functions with PLC-1 to regulate IP3 production, calcium release, and contraction of the spermatheca. Filamin may function to sense stretch caused by entering oocytes and to trigger constriction. These findings establish a link between filamin and calcium signaling that may apply to similar signaling pathways in other systems.
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影响因子：
3.7
作者：
DeMaso CR;Kovacevic I;Uzun A;Cram EJ
通讯作者：
Cram EJ
DOI：
10.1038/nrm3112
发表时间：
2011-05
期刊：
Nature reviews. Molecular cell biology
影响因子：
--
作者：
通讯作者：
--
影响因子：
3.5
作者：
Farrington-Rock, Claire;Kirilova, Veneta;Krakow, Deborah
通讯作者：
Krakow, Deborah
影响因子：
2.9
作者：
Ithychanda, Sujay Subbayya;Qin, Jun
通讯作者：
Qin, Jun
影响因子：
2.5
作者：
Altun, Zeynep F.;Chen, Bojun;Wang, Zhao-Weng;Hall, David H.
通讯作者：
Hall, David H.