Elucidating the Mechanisms of Intercellular Movement

University Of Pennsylvania, Philadelphia PA

Investigators

Abstract

Cells within both plants and animals must be able to communicate with each other to coordinate growth, development and function. In plants, many proteins move between cells via structures referred to as plasmodesmata - channels that link neighboring cells and provide a direct pathway for the exchange of information and materials. These same channels also serve as conduits for the movement of viruses between plant cells and thus the systemic spread of disease throughout the plants. In this project an important protein in root development and leaf vein patterning in many different species of plants, termed SHORT-ROOT (SHR), is examined. Loss of SHR movement results in abnormal development and stunting of growth. Here SHR is used as a model for understanding how plant proteins move between cells and coordinate development and as a potential tool for understanding how economically important plant virus move between cells. This research engages students from all levels and is used in the inspiration of art exhibits produced by undergraduate students in the Philadelphia area. Undergraduate students at the University of Pennsylvania are actively involved in this research, as are art students from the Philadelphia Academy of Fine Arts (PAFA) who draw inspiration from the research for science inspired designs. Cell-to-cell communication is essential for the development and survival of multicellular organisms. In plants, such exchange of information is frequently achieved by the intercellular trafficking of transcription factors. It is now recognized that these proteins move via plasmodesmata, highly specialized membrane-lined channels interconnecting individual cells. However, the mechanisms by which proteins access plasmodesmata remain unknown. The movement of the non-cell-autonomous transcription factor, SHORT-ROOT (SHR) is highly regulated at the cellular level and requires an active endomembrane system, intact microtubules and interaction with endosome-associated proteins. Proteomic and ligand induced binding assay are used to identify proteins that interact with SHR and promote the cell-to-cell movement of SHR. Movement of SHR serves as a tractable entry point into understanding the widespread movement of protein in plants. This award was co-funded by the Cellular Dynamics and Function Program and the Genetic Mechanisms Program, both in the Division of Molecular and Cellular Biosciences, in the Directorate for Biological Sciences. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.