The nuclear envelope (NE) hosts a unique population of proteins that perform essential cellular functions, including signal transduction, lipid metabolism, chromatin organization, and nucleocytoplasmic transportation. About 300-400 proteins have been found at the NE in both humans and yeasts, and mutations in NE components are responsible for numerous human genetic disorders that are collectively known as “nuclear envelopathies, including progeria (early aging diseases), muscle dystrophy, neural degeneration, and immune defects. Compared to humans, much less is known about the composition of the plant NE proteome, and available evidence indicates that the plant NE proteome is largely distinct from that in animals and yeasts. We have recently developed a proximity labeling-coupled label-free quantitative mass spectrometry (PL-LFQMS) approach, which enables NE membrane protein identification in plants with unprecedented specificity (News and Publications). We identified more than a dozen new plant NE proteins and are currently investigating the biological significance of those proteins in plant development and stress responses.
We are now focusing on investigating the function of one of our newly identified plant NE protein PNET14 that possesses a malectin-like domain. The malectin-like domain has been proposed to recognize and bind Glc2-N-glycan and found in many receptor-like kinases in plants. However, their function has not been well understood. What makes PNET14 particularly interesting is that it is localized to the inner nuclear membrane, a subcellular localization that is barely reported to be involved in signaling perception and accumulation of receptor-like kinases. We propose that PNET14 may sense some novel carbohydrate-related signals associated with the nuclear membrane, which is potentially important for function of the plant nucleus.
The undergraduate will clone the full-length cDNA of PNET14 gene and several closely related PNET14 homologs and then fuse those cDNAs with GFP and GUS tag. She/he will then determine the subcellular localization of PNET14 and its homologs fused to GFP using transient expression and confocal fluorescence microscopy. Meanwhile, she/he will determine the tissue specific expression pattern of PNET14 and its homologs using the GUS constructs and stable expression in Arabidopsis. Furthermore, the students will determine the loss of function phenotypes of PNET14 and its homologs in Arabidopsis using T-DNA insertion mutant lines. During this project, the student will learn new cell biology concepts such as nuclear membrane biology, nuclear pore complex and related nucleocytoplasmic transport. They will also learn valuable bench skills such as molecular cloning, fluorescence microscopy, genotyping, and construction of transgenic plants.
Students with strong interests in plant biology, cell biology, and genetics will find the experience most rewarding. Excellent attention to detail and good record-keeping skills are necessary. Students with a flexible Spring 2022 class schedule are encouraged to apply.