NSF/MCB-BSF:Elucidating the role of ERM proteins in cytoskeletal orientation in a contractile tissue

NSF/MCB-BSF：阐明 ERM 蛋白在收缩组织中细胞骨架定向中的作用

• 批准号: 1816640
• 负责人: Erin Cram
• 金额: $ 59.86万
• 依托单位: Northeastern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1816640&HistoricalAwards=false
• 关键词: NSF; MCB; BSF; Elucidating; role

Animal bodies are full of biological tubing: blood vessels, lung airways, intestines, the reproductive system, and ducts and glands of various sorts. These tubes are composed of cells that squeeze and relax to move contents through the tubes in the correct direction, at the correct rate, and in a coordinated manner. The squeezing is driven by a molecular machine called the acto-myosin cytoskeleton, which is comprised of tiny motors that pull on a girdle-like mesh of fibers to contract the cells. The "girdle" must be lined up properly and coordinated between cells for tubes to work properly. However, little is known about how this "girdle" knows how to squeeze the right amount at the right time or how its fiber alignment changes in response to changing mechanical conditions. To better understand how this process works, the Cram and Zaidel-Bar labs study the reproductive system of a small nematode worm called C. elegans. This worm can produce its body weight in babies every day, so many eggs have to be squeezed through the reproductive system in a coordinated and robust manner. This system was chosen because the worm is transparent, which makes it easy to see the response of the "girdle" in real time in a living animal, and the system uses the same cellular components as do other animals. This project will determine, molecularly, how the worm's acto-myosin "girdle" responds to the stretch of eggs entering and exiting the system, and how it contracts just the right amount to push the eggs through in the right direction and without mangling them. Because similar genes regulate acto-myosin contraction in many animals, the results should be broadly applicable up to and including primates. Broader impacts of this project include developing materials to help undergraduates learn how to be scientists, and involving high school teachers in research experiences and helping them design projects that they can take back to their classrooms.Actin networks in contractile cells, such as the smooth muscle and endothelial cells of the vasculature, are critical for cell contractility, motility, and tissue function. But, how do cells organize their actin cytoskeletons in response to changing mechanical conditions? And how is cytoskeletal alignment coordinated between cells to produce a cohesive tissue-level response? To address these questions, the Cram and Zaidel-Bar labs have developed a new in vivo model system: the C. elegans spermatheca, a stretch-responsive and contractile tissue in the nematode reproductive system. The Cram lab has discovered that during the first ovulation, myosin becomes activated and pulls a network of loose actin fibers into aligned and oriented stress-fiber like acto-myosin bundles. In a screen through all actin binding proteins in C. elegans, the ezrin-radixin-moesin (ERM) proteins Merlin (NFM-1) and Ezrin (ERM-1) were identified as key tissue-level regulators of actin fiber orientation. ERM proteins can bind plasma membrane, actin, and transmembrane proteins, placing them ideally to regulate cell responses to stretch. Using live imaging, biochemical, genetic, and optogenetic approaches, this collaborative team will elucidate the role ERM proteins play in actin organization within and between cells of the spermatheca. Aim 1 will determine the dynamics of the ERM proteins during spermathecal stretch and contraction and discover the mechanism by which these proteins regulate the apical and basal actin networks and tissue-level organization of the actin cytoskeleton. Aim 2 will determine how ERM proteins both regulate and are regulated by the small GTPase Rho, including analysis of a novel regulator C45G9.7/Tip1, to promote cytoskeletal organization and orientation. This project will reveal that Merlin and Ezrin, important regulators of the actin cytoskeleton, act not only within individual cells, but in tissue-level coordination of actin cytoskeletal alignment. Novel roles for ERM proteins in cell response to physiological levels of strain will be revealed, including, how the cytoskeleton adapts its orientation and alignment for optimal tissue contractility. The Broader Impacts of this project include 1) developing a structured mentoring approach for undergraduate research and 2) involving science teachers in independent research with the goal of enhancing K-12 STEM education.This collaborative US/Israel project is supported by the US National Science Foundation and the Israeli Binational Science Foundation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

动物体内充满了生物管道：血管、肺气道、肠道、生殖系统以及各种各样的导管和腺体。这些管道由细胞组成，细胞挤压和放松，以正确的方向，正确的速度和协调的方式移动内容物通过管道。这种挤压是由一种叫做肌动蛋白细胞骨架的分子机器驱动的，这种分子机器由微小的马达组成，它们拉动一个类似环带的纤维网来收缩细胞。“腰带”必须正确排列并在单元之间协调，以便管道正常工作。然而，关于这种“腰带”如何知道如何在正确的时间挤压正确的量，或者它的纤维排列如何响应不断变化的机械条件而变化，人们知之甚少。为了更好地了解这一过程是如何工作的，克拉姆和扎德尔-巴尔实验室研究了一种叫做C.优美的这种蠕虫每天都能在婴儿身上产生它的体重，所以许多卵必须以协调和稳健的方式通过生殖系统挤压。选择这个系统是因为蠕虫是透明的，这使得它很容易看到“腰带”的反应在真实的时间在一个活的动物，和系统使用相同的细胞成分做其他动物。这个项目将从分子上确定蠕虫的肌动球蛋白“腰带”如何对进入和离开系统的卵的伸展做出反应，以及它如何收缩恰到好处的量以将卵推向正确的方向，而不会破坏它们。因为在许多动物中，类似的基因调节肌动蛋白-肌球蛋白的收缩，所以研究结果应该广泛适用于灵长类动物。该项目的更广泛的影响包括开发材料，帮助本科生学习如何成为科学家，并参与高中教师的研究经验，并帮助他们设计项目，他们可以带回到他们的教室。收缩细胞中的肌动蛋白网络，如血管平滑肌和内皮细胞，是细胞收缩性，运动性和组织功能的关键。但是，细胞如何组织肌动蛋白细胞骨架以应对不断变化的机械条件？细胞间的细胞骨架排列是如何协调的，从而产生一种有凝聚力的组织水平反应？为了解决这些问题，Cram和Zaidel-Bar实验室开发了一种新的体内模型系统：C。线虫受精囊是线虫生殖系统中的一种伸缩性组织。克拉姆实验室发现，在第一次排卵期间，肌球蛋白被激活，并将松散的肌动蛋白纤维网络拉成对齐和定向的应力纤维，如肌动蛋白-肌球蛋白束。在筛选C.在elegans中，ezrin-根蛋白-膜突蛋白（ERM）蛋白Merlin（NFM-1）和Ezrin（ERM-1）被鉴定为肌动蛋白纤维取向的关键组织水平调节剂。ERM蛋白可以结合质膜，肌动蛋白和跨膜蛋白，理想地将它们放置在调节细胞对拉伸的反应中。利用实时成像，生物化学，遗传学和光遗传学方法，这个合作团队将阐明ERM蛋白在受精囊细胞内和细胞间肌动蛋白组织中的作用。目的1将确定的ERM蛋白在受精囊拉伸和收缩的动力学，并发现这些蛋白调节肌动蛋白细胞骨架的顶端和基底肌动蛋白网络和组织水平的组织的机制。目的2将确定ERM蛋白如何调节和被小G蛋白Rho调节，包括分析一个新的调节因子C45G9.7/Tip 1，以促进细胞骨架的组织和方向。该项目将揭示，梅林和埃兹林，肌动蛋白细胞骨架的重要调节剂，不仅在单个细胞内，但在组织水平的协调肌动蛋白细胞骨架排列。ERM蛋白在细胞对生理水平的应变反应中的新作用将被揭示，包括细胞骨架如何适应其方向和排列以获得最佳的组织收缩性。该项目的更广泛影响包括：1）为本科生研究开发一种结构化的指导方法; 2）让科学教师参与独立研究，以加强K-12 STEM教育。以色列项目得到美国国家科学基金会和以色列两国科学基金会的支持。该奖项反映了NSF的法定使命，并通过评估被认为值得支持使用基金会的知识价值和更广泛的影响审查标准。

项目成果

Tension-dependent RHGF-1 recruitment to stress fibers drives robust spermathecal tissue contraction.

• DOI: 10.1083/jcb.202203105
• 发表时间: 2023-02-06
• 期刊: The Journal of cell biology

An integrin binding motif in TLN-1/talin plays a minor role in motility and ovulation.

• DOI: 10.17912/micropub.biology.000726
• 发表时间: 2023
• 期刊: microPublication biology
• 作者: Sadeghian, Fereshteh;Ibrahim, Ibrahim;Ravichandran, Lokesh;Henderson, Grace;Acharya, Anisha;Wang, Lianzijun;Lee, Myeongwoo;Cram, Erin J
• 通讯作者: Cram, Erin J

FLN-1/filamin is required to anchor the actomyosin cytoskeleton and for global organization of sub-cellular organelles in a contractile tissue.

• DOI: 10.1002/cm.21633
• 发表时间: 2020-10
• 期刊: Cytoskeleton (Hoboken, N.J.)
• 作者: Kelley CA;Triplett O;Mallick S;Burkewitz K;Mair WB;Cram EJ
• 通讯作者: Cram EJ