How yeast sense direction in shallow pheromone gradients

酵母如何感知浅信息素梯度中的方向

• 批准号: 1818067
• 负责人: David Stone
• 金额: $ 90万
• 依托单位: University of Illinois at Chicago
• 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 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1818067&HistoricalAwards=false
• 关键词: How; yeast; sense; direction; shallow

This project will contribute to our understanding of gradient sensing, the ability of cells to sense small differences in chemical concentration across their surfaces, and thereby locate the source of the stimulus. This phenomenon is essential for the development and health of all organisms. The principal investigator uses yeast cells as a model to study the molecular mechanisms underlying gradient sensing, which are thought to be broadly applicable to cells in more complex organisms as well. During this project period, the principal investigator and his postdoctoral scientist will mentor select biology students from nearby Malcolm X College (MXC), one of the City Colleges of Chicago, in an effort to enhance their chances of graduating from a four-year institution with a BS in a STEM field. The proposed undergraduate research and mentoring program is designed to inspire, instruct, advise, and support underrepresented students who may be interested in a STEM career. The investigation will also provide students and the postdoctoral scientist with interdisciplinary training through interactions with collaborators who are experts in diverse areas. Because the project is at the interface of math and biology, researchers on each team will gain a better understanding of the methods used by those in the other discipline.The best-known gradient-stimulated cellular outputs, chemotaxis (directed cell movement), and chemotropism (directed cell growth), are required for a wide range of biologic processes. Although they ultimately exhibit quite different behavior, chemotactic and chemotropic cells face similar challenges: the responding cell must sense small differences in chemical concentration across its surface, determine the direction of the gradient source, and polarize its cytoskeleton toward it. The mating response of the budding yeast S. cerevisiae is chemotropic: mating cells interpret complex pheromone gradients and polarize their growth in the direction of the closest partner. Like many chemotaxing cells, yeast use G protein-coupled receptors to detect mating pheromone secreted by potential partners and thereby direct their growth toward the nearest pheromone source. The goal of this project is to understand how the chemotropic growth site is established before polarization of the cytoskeleton, and how the cell responds to changes in gradient direction. Various models have been proposed to explain how yeast interpret shallow pheromone gradients in vivo, but none satisfactorily answers the fundamental and long-standing question: how do the cells switch from the default polarity site they use for cell division to establish a chemotropic site, despite a near zero signal-to-noise ratio? Based on discoveries made during a previous project, the principal investigator proposed a model that answers this question. The working hypothesis is that mating yeast initially ignore the pheromone gradient, as they first colocalize and concentrate signaling and trafficking proteins at the default site, building a "gradient tracking machine" (GTM). Once assembled, the GTM moves along the plasma membrane to the point of maximal pheromone concentration, where it marks the chemotropic site. The priorities of this investigation are to learn how the GTM is assembled, how it moves to the chemotropic site, and how it steers chemotropic growth in response to changes in gradient direction. These questions will be answered using imaging, genetic, optogenetic, biochemical, and computational approaches, leading to a deeper understanding of chemical gradient sensing. Because little is known about how gradient-aligned cell polarity is established during the chemotropic responses of other eukaryotes, general principles are likely to emerge that will broadly influence the study of chemotropic phenomena. Moreover, many of the questions posed in this investigation are pertinent to other transmembrane signaling systems, and the findings are expected to reveal generally relevant mechanisms.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.

该项目将有助于我们理解梯度传感，即细胞感知其表面化学浓度微小差异的能力，从而定位刺激源。这种现象对于所有生物体的发育和健康至关重要。主要研究人员使用酵母细胞作为模型来研究梯度传感的分子机制，这被认为也广泛适用于更复杂生物体的细胞。在该项目期间，首席研究员和他的博士后科学家将指导从附近的芝加哥城市学院之一马尔科姆 X 学院 (MXC) 挑选出来的生物学学生，以提高他们从四年制大学毕业的机会STEM 领域的学士学位。拟议的本科生研究和指导计划旨在激励、指导、建议和支持可能对 STEM 职业感兴趣的代表性不足的学生。该调查还将通过与不同领域的专家合作者的互动，为学生和博士后科学家提供跨学科培训。由于该项目处于数学和生物学的交汇处，每个团队的研究人员将更好地了解其他学科所使用的方法。最著名的梯度刺激细胞输出、趋化性（定向细胞运动）和趋化性（定向细胞生长）是多种生物过程所必需的。尽管它们最终表现出完全不同的行为，但趋化细胞和趋化细胞面临着相似的挑战：响应细胞必须感知其表面化学浓度的微小差异，确定梯度源的方向，并将其细胞骨架朝它极化。芽殖酵母酿酒酵母的交配反应是趋化性的：交配细胞解释复杂的信息素梯度，并使它们的生长向最接近的伙伴的方向极化。与许多趋化细胞一样，酵母使用 G 蛋白偶联受体来检测潜在伴侣分泌的交配信息素，从而引导它们向最近的信息素来源生长。该项目的目标是了解在细胞骨架极化之前如何建立趋化生长位点，以及细胞如何响应梯度方向的变化。人们提出了各种模型来解释酵母如何解释体内的浅信息素梯度，但没有一个模型令人满意地回答了长期存在的基本问题：细胞如何从用于细胞分裂的默认极性位点切换到建立趋化性位点，尽管信噪比接近于零？根据之前项目的发现，首席研究员提出了一个模型来回答这个问题。工作假设是，交配酵母最初忽略信息素梯度，因为它们首先在默认位点共定位并集中信号传导和运输蛋白质，构建“梯度跟踪机”（GTM）。一旦组装完毕，GTM 就会沿着质膜移动到最大信息素浓度点，在那里它标志着趋化位点。这项研究的重点是了解 GTM 是如何组装的，它如何移动到趋化位点，以及它如何引导趋化生长以响应梯度方向的变化。这些问题将通过成像、遗传学、光遗传学、生物化学和计算方法得到解答，从而加深对化学梯度传感的理解。由于人们对其他真核生物的趋化反应过程中如何建立梯度排列的细胞极性知之甚少，因此可能会出现广泛影响趋化现象研究的一般原理。此外，本次调查中提出的许多问题与其他跨膜信号系统相关，研究结果预计将揭示普遍相关的机制。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和技术进行评估，被认为值得支持。更广泛的影响审查标准。

项目成果

Quantitative proteomics reveals a Gα/MAPK signaling hub that controls pheromone-induced cellular polarization in yeast

定量蛋白质组学揭示了控制酵母中信息素诱导的细胞极化的 Gα/MAPK 信号中枢

• DOI: 10.1016/j.jprot.2019.103467
• 发表时间: 2019-09
• 期刊: Journal of Proteomics
• 影响因子: 3.3
• 作者: Waszczak, Nicholaz;DeFlorio, Reagan;Ismael, Amber;Cheng, Naiyuan;Stone, David E.;Metodiev, Metodi V.
• 通讯作者: Metodiev, Metodi V.

Phosphorylated Gβ is a directional cue during yeast gradient tracking

磷酸化 Gβ 是酵母梯度跟踪过程中的方向提示

• DOI: 10.1126/scisignal.abf4710
• 发表时间: 2021-05
• 期刊: Science Signaling
• 影响因子: 7.3
• 作者: Abdul;Venegas, Leon A.;Wang, Xin;Puerner, Charles;Arkowitz, Robert A.;Kay, Brian K.;Stone, David E.
• 通讯作者: Stone, David E.

A member of the claudin superfamily influences formation of the front domain in pheromone-responding yeast cells

紧密蛋白超家族的成员影响信息素响应酵母细胞中前域的形成

• DOI: 10.1242/jcs.260048
• 发表时间: 2023-01
• 期刊: Journal of Cell Science
• 影响因子: 4
• 作者: Sukumar, Madhushalini;DeFlorio, Reagan;Pai, Chih;Stone, David E.
• 通讯作者: Stone, David E.

Mating yeast cells use an intrinsic polarity site to assemble a pheromone-gradient tracking machine

交配酵母细胞使用固有极性位点来组装信息素梯度跟踪机

• DOI: 10.1083/jcb.201901155
• 发表时间: 2019-09
• 期刊: Journal of Cell Biology
• 影响因子: 7.8
• 作者: Wang, Xin;Tian, Wei;Banh, Bryan T.;Statler, Bethanie;Liang, Jie;Stone, David E.
• 通讯作者: Stone, David E.

Gradient tracking in mating yeast depends on Bud1 inactivation and actin-independent vesicle delivery

交配酵母中的梯度追踪取决于 Bud1 失活和不依赖于肌动蛋白的囊泡递送

• DOI: 10.1083/jcb.202203004
• 发表时间: 2022-12-05
• 期刊: Journal of Cell Biology
• 影响因子: 7.8
• 作者: Wang, Xin;Pai, Chih;Stone, David E.
• 通讯作者: Stone, David E.