Genetic and biophysical analysis of morphogen gradient formation

形态素梯度形成的遗传和生物物理分析

基本信息

批准号：
10723239
负责人：
Gavin S Schlissel
金额：
$ 12.5万
依托单位：
WHITEHEAD INSTITUTE FOR BIOMEDICAL RES
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-09-01 至 2025-08-31
项目状态：
未结题

项目摘要

Principal Investigator: Schlissel, Gavin Project summary Animal development and physiology require regular communication among cell types embedded in tissues. Cellular communication commonly relies on signaling proteins, which can transit the space between cells and relay information across a wide range of spatial scales from nanometers to meters. Proper control of signaling range is strictly necessary during animal development, and dysregulation of signaling range can result in a spectrum of embryonic lethal conditions or developmental disorders. The patterning gradient formed by a signaling protein reflects the signaling protein’s ability to travel through the extracellular matrix, which is an amalgam of protein, sugar and lipids that organize cells in natural tissues. Although signaling proteins are thought to diffuse from their source to their target, many proteins violate the assumptions of free diffusion and instead show context-dependent differences in their signaling range. For example, Sonic Hedgehog family developmental morphogens form signaling gradients over ~10µm in the testes, ~50µm in the developing neural tube or in adult hair follicles, and ~300µm in developing long bones. Notably, tissues in which Sonic Hedgehog forms longer signaling gradients tend to express Scube family extracellular matrix proteins, and Scube family proteins can dramatically extend Sonic Hedgehog signaling gradients in cell culture. I suspect that tissue-specific differences in signaling range might reflect direct regulation of Sonic Hedgehog’s diffusion rate, and that regulated diffusion of Hedgehog might reflect a broadly used strategy to control the size of signaling gradients in animals. To understand how morphogens and the extracellular matrix interact to generate appropriately sized signaling gradients, I will measure variation in protein diffusion both between diverse signaling proteins, and between distinct extracellular environments. I will apply this mechanistic understanding to discover how biochemical features of signaling proteins and the extracellular matrix result in size variation among signaling gradients as well as morphological variation among the anatomical features that they pattern. To that end, I propose the following specific aims: 1) Understand how Scube family proteins modify hedgehog diffusion by tracking single particles of sonic hedgehog diffusing through the extracellular matrix. 2) Discover which biochemical features of a signaling protein affect its diffusion rate through the extracellular matrix by developing synthetic morphogens, in which diffusion can be uncoupled from downstream signal transduction. 3) Identify extracellular matrix modifiers of protein diffusion that contribute to tissue- or organism-specific signaling gradient size discrepancies by genetically simulating tissue-specific extracellular matrix variation K99/R00 Fellowship Application October 2022

首席研究员：施利塞尔，加文项目摘要动物发育和生理需要在组织中嵌入的细胞类型之间进行定期通信。蜂窝通信通常依赖于信号蛋白，该信号蛋白可以在细胞和从纳米到米的各种空间尺度的中继信息。正确控制信号在动物发育过程中，严格必要范围，信号范围的失调可能导致胚胎致死疾病或发育障碍的频谱。信号蛋白形成的图案梯度反映了信号蛋白的行进能力通过细胞外基质，该基质是蛋白质，糖和脂质的汞合金，它们在天然中组织细胞组织。尽管认为信号蛋白被认为从其源到目标弥散，但许多蛋白质都违反了自由扩散的假设，而是在其信号范围内显示出上下文依赖性差异。为了例如，在测试中，声音刺猬家族开发形态剂在〜10µm以上形成信号传导梯度，在发育中的神经管或成年毛发中〜50µm，在长骨中〜300µm。尤其，声音刺猬形成更长的信号梯度的组织倾向于表达细胞外的scube家族基质蛋白和Scube家族蛋白可以极大地扩展细胞中的声音刺猬信号梯度文化。我怀疑信号范围内组织特异性差异可能反映了声音的直接调节刺猬的扩散率以及受监管的刺猬扩散可能反映了广泛使用的策略控制动物信号梯度的大小。了解形态和细胞外基质如何相互作用以生成适当尺寸的信号传导梯度，我将测量蛋白质扩散的变化在不同的信号蛋白之间以及不同的细胞外环境之间。我将应用这种机械理解以发现信号蛋白和细胞外基质的生化特征如何导致信号传导梯度之间的尺寸变化以及解剖学特征之间的形态变化他们模式。为此，我提出了以下具体目标： 1）了解Scube家族蛋白如何通过跟踪声音的单个颗粒来修饰刺猬的扩散刺猬通过细胞外基质扩散。 2）发现信号蛋白的生化特征会影响其通过细胞外基质通过开发合成形态剂，其中可以从中脱离扩散下游信号转导。 3）确定有助于组织或生物特异性的蛋白质扩散的细胞外基质修饰符通过基因模拟组织特异性细胞外基质的信号梯度尺寸差异变化 K99/R00奖学金申请 2022年10月