Submitted by Yangnan Gu on
Plants evolved a highly effective innate immune system to defend against assorted pathogens. Cell surface localized receptor-like kinases and receptor-like proteins, sense conserved pathogen-derived molecular patterns and activate pattern-triggered immunity (PTI). Although some pathogens have evolved a plethora of secreted proteins termed effectors to undermine host PTI, plants express a second group of immune receptors named nucleotide-binding leucine-rich repeat (NLR) proteins. NLRs directly or indirectly recognize pathogen effectors and activate effector-triggered immunity (ETI) to restrict pathogen growth.
While equipped with powerful defense tools, plants also developed sophisticated mechanisms to prevent autoimmune activation, which is essential to avoid misfiring in the absence of pathogens. Among them, karyopherin-b family proteins appear to play an essential role. Karyopherin-bs are nuclear transport receptors that mediate the passage of macromolecules across the nuclear pore. In this project, we study a karyopherin called KA120. Mutations in KA120 lead to strong immune activation in plants in the absence of pathogen infections, suggesting an essential role of this karyopherin in suppressing autoimmune activation. This project aims to understand the mechanism of how KA120 participates in plant immune regulation.
We have profiled the in vivo cargo of KA120 in plants and identified a number of interesting candidates that are potentially regulated by KA120 to modulate plant immune activation. The SPUR student will be involved in cloning part of these new candidates from Arabidopsis genome and fuse them with GFP and other molecular tags. Subsequently, they will transiently express those clones in tobacco and observe their subcellular localization and co-localization with KA120. They will also perform western blot and immunoprecipitation to test whether those candidates are directly interacting with KA120 in vivo and how KA120 may regulate their subcellular localization and protein activity.
Through this project, the student will learn essential molecular and cellular techniques used in modern biological research, including molecular cloning, fluorescence imaging, and immunoblotting. They will also learn various plant biology research tools, including plant gene cloning, transient heterologous expression, and generation 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.