Differentiation in Yeast: Mechanisms of Mating and Meiosis

酵母的分化：交配和减数分裂的机制

基本信息

批准号：
10227983
负责人：
Mark David Rose
金额：
$ 39.86万
依托单位：
GEORGETOWN UNIVERSITY
依托单位国家：
美国
项目类别：
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://reporter.nih.gov/project-details/10227983
关键词：
Address Adenine Aneuploidy Animal Model Animals Biological Cell Wall Cell fusion Cell membrane Cell physiology Cells Cellular biology Complex Defect Degradation Pathway Development Diploidy Disease Disseminated Malignant Neoplasm Eukaryotic Cell Extracellular Matrix Fertilization Genes Genetic Screening Genetic Transcription Germ Cells Giant Cells Goals Haploidy Health Homologous Gene Human Lead Mediating Meiosis Membrane Membrane Fusion Messenger RNA Methylation Methyltransferase Mitosis Modification Molecular Mus Myoblasts Nuclear Envelope Nuclear Fusion Organism Partner in relationship Pathologic Pathway interactions Plants Process Proteins Regulation Research Role Saccharomyces cerevisiae Saccharomycetales Sexual Reproduction Signal Transduction Somatic Cell Sterility Testing Tissues Transcriptional Regulation Translational Regulation Viral Yeasts fungus muscle form novel protein degradation zygote

项目摘要

Eukaryotic cells fuse during fertilization to produce diploid zygotes that go on to differentiate into specialized cells during development. Somatic cell fusion also occurs during development to produce multinucleate tissues, such as myoblast fusion to form muscle. Diploid organisms may then undergo meiosis to produce haploid gametes for subsequent fertilization, completing the cycle of sexual reproduction. Cell fusion and meiosis must be tightly regulated. Inappropriate cell fusion, as occurs in some virally-infected cells and metastatic cancers, results in pathological syncytia. Despite advances in elucidating the process of cell fusion, much remains unknown. Meiotic defects may cause aneuploidy, or even sterility. Recent research revealed that meiotic regulation is surprisingly complex. Overlaid on waves of transcriptional regulation are complex layers of mRNA modification and translational regulation which are thought to provide exquisite temporal control. However, much remains to be learned about how meiosis is regulated. The long-term goals of the research in my lab are to understand the fundamental, conserved molecular mechanisms of cell fusion, nuclear fusion, and meiotic regulation using one of the most powerful model organisms, the budding yeast Saccharomyces cerevisiae. During yeast mating and somatic cell fusion, cells must signal that they are in contact and competent to fuse, remove the extracellular matrix separating them, and fuse the plasma membranes. Each step is only poorly understood. We have shown that in yeast, as in mouse myoblasts, Cdc42p is a key regulator of cell fusion. We will address how cell contact regulates Cdc42p and how Cdc42p in turn mediates cell fusion, focusing on membrane curvature and the cell wall integrity pathway. Using a novel genetic screen, we will pursue identification of the yeast membrane fusogen. After mating and cell fusion, many induced proteins may be hazardous and must be rapidly degraded. We discovered that Srl4p stabilizes mating-induced proteins by inhibiting a branch of the proteasomal degradation pathway. We will examine how Srl4p differentially regulates the turnover of proteins in mating and mitosis. After fertilization in many organisms, the pronuclei fuse. Nuclear fusion is a challenging biological problem – how do the two membranes fuse sequentially and in register? We identified Kar5p, a protein conserved in plants, animals, and fungi, as mediating nuclear envelope fusion; however, its precise role is unknown. We will test our hypothesis that Kar5p acts as a novel inner nuclear envelope fusogen. In meiosis, mRNA N6-adenine methylation has been revealed to be a critical regulator, although its functions are not yet understood. Kar4p is the yeast homologue of human METTL14, a core component of the methyl-transferase. Surprisingly, we found that Kar4p regulates both meiotic transcription and meiotic protein levels. We will examine how Kar4p regulates meiosis at multiple levels, testing potential roles in transcription, translational regulation, and mRNA modification. Our studies will aid the understanding of basic conserved mechanisms of cell fusion, nuclear membrane fusion, and meiosis.

真核细胞在受精过程中融合产生二倍体受精卵，并继续分化为特化的受精卵体细胞在发育过程中也会发生融合，产生多核。组织，例如成肌细胞融合形成肌肉，然后可以经历减数分裂以产生肌肉。单倍体配子用于随后的受精，完成有性生殖的周期和细胞融合。减数分裂必须受到严格调控，如某些病毒感染的细胞中发生的那样。尽管在阐明细胞融合过程方面取得了进展，但转移性癌症会导致病理性合胞体。最近的研究表明，减数分裂缺陷可能会导致非整倍体，甚至不育。减数分裂调控非常复杂，叠加在转录调控波上也很复杂。 mRNA 修饰和翻译调控层被认为提供了精致的时间然而，关于减数分裂的长期目标还有待了解。我实验室的研究是了解细胞融合、核细胞融合的基本、保守的分子机制。使用最强大的模型生物之一——芽殖酵母进行融合和减数分裂调节在酵母交配和体细胞融合过程中，细胞必须发出信号表明它们处于酵母交配状态。接触并能够融合，去除分隔它们的细胞外基质，并融合血浆我们对酵母细胞和小鼠成肌细胞中的每个步骤都知之甚少。 Cdc42p 是细胞融合的关键调节因子，我们将讨论细胞接触如何调节 Cdc42p 以及 Cdc42p 如何参与细胞融合。转介导细胞融合，重点关注膜曲率和细胞壁完整性途径。遗传筛选，我们将在交配和细胞融合后进行酵母膜融合剂的鉴定。许多诱导蛋白可能是危险的，必须快速降解。我们发现 Srl4p 可以稳定下来。我们将研究如何通过抑制蛋白酶体降解途径的一个分支来产生交配诱导的蛋白质。 Srl4p 在许多受精后对交配和有丝分裂中的蛋白质周转进行差异性调节。生物体中，原核融合是一个具有挑战性的生物学问题——两个膜如何融合。我们鉴定出 Kar5p，一种在植物、动物和真菌中保守的蛋白质，介导核膜融合；然而，我们将检验我们的假设：Kar5p。在减数分裂中，mRNA N6-腺嘌呤甲基化已被揭示。尽管 Kar4p 是人类酵母同源物，但其功能尚不清楚。令人惊讶的是，METTL14 是甲基转移酶的核心成分，我们发现 Kar4p 可以调节这两种酶。我们将研究 Kar4p 如何在多个减数分裂中调节减数分裂。水平，测试在转录、翻译调控和 mRNA 修饰中的潜在作用。帮助理解细胞融合、核膜融合和减数分裂的基本保守机制。