拟南芥棕榈酰基转移酶（PAT1/2/3/4/8）调控花粉管接纳的功能和机理研究

Protein palmitoylation, or S-acylation, is a reversible post-translational modification that is catalyzed by protein S-acyl transferases (PATs). Substrates of S-acylation mostly include key signaling proteins, such as receptor-like kinases, calcium sensors, small GTPases, and proteins involved in vesicular trafficking. S-acylation modifies the subcellular localization, activity, and interacting profiles of substrates proteins, and therefore plays critical roles in their function. Plant genomes encode a large number of PATs. However, due to redundancy, few plant PATs have been functionally characterized. The applicant has been working on generating hierarchy Arabidopsis PAT mutants by using the genome-editing technique CRISPR/Cas9. One of the mutants that have been generated is defective in five highly homologous PATs, and thus named pentapat1. Preliminary phenotypic analysis showed that pentapat1 is impaired in pollen tube reception, which resulted in significantly reduced male transmission and fertility. Although a few female factors have been characterized in pollen tube reception, male factors that are critical for this process are still unclear. Therefore, this proposal aims at a deep understanding of the molecular mechanism underlying PENTAPAT1-mediated pollen tube reception, by finely characterizing the mutant phenotype, screening and identifying of PENTAPAT1 substrates in pollen tubes, as well as characterizing the genetic relations between PENTAPAT1 substrates and known female factors during pollen tube reception.

S型棕榈酰化是一种可逆的蛋白质翻译后修饰，由棕榈酰基转移酶（PAT）催化，这种修饰通过改变底物蛋白的亚细胞定位及活性，从而调控其功能。已知底物大都参与细胞信号传导过程。植物基因组中编码大量的PAT，但仅少数PAT的功能得以揭示。申请人创制了拟南芥五个棕榈酰基转移酶的高阶突变体(pentapat1)。分析发现该突变体的花粉管接纳过程有异常，从而导致育性降低。目前已知助细胞受体蛋白及第二信使参与花粉管接纳，然而对于花粉管中参与这一过程的因子知之甚少。本项目拟分析确认pentapat1突变体的表型；利用棕榈酰蛋白组学技术，结合候选蛋白的定点突变及反向遗传学手段，筛选鉴定PENTAPAT1在花粉管中的底物；通过遗传学分析及分子间互作，解析花粉管质膜上PENTAPAT1及其蛋白底物与助细胞受体的关系。以期揭示棕榈酰化是如何参与调控植物的有性生殖过程，为深入理解雌雄配子体间的信号交流提供新的信息。

“拟南芥棕榈酰基转移酶（PAT1/2/3/4/8）调控花粉管接纳的功能和机理研究” 的研究目的是揭示棕榈酰化是如何参与调控植物的有性生殖过程，为深入理解雌雄配子体间的信号交流提供新的信息。..课题组在过去的4年间，在以下3个方面取得了较突出的成果。1、发现了拟南芥棕榈酰基转移酶YKT61作为R-SNARE，参与多个囊泡-靶膜的融合过程调节植物育性；2、发现了拟南芥棕榈酰基转移酶PAT10修饰 CBL10/SCaBP8 以调控其液泡定位和响应盐胁迫。3、揭示了根分生区发育过程中PLT1的转录调控机制..主持人在项目执行期间，发表本基金标注的SCI论文15篇，以通讯作者或共同通讯作者11篇，包括Plant Cell、Mol Plant、Plant Physiol、Plant J、JIPB、以及PLOS Genet。研究成果受到广泛关注。..项目执行的4年间，培养毕业硕士研究生5人，其中2人继续攻读博士。