Characterization of Plasmodesmal Channel Protein

Principal Investigator:

Jung-Youn Lee (Professor, Plant and Soil Sciences)

Principal Investigator's Website:

www.dbi.udel.edu/People/younlee.html

Funding:

(Need funding info)

Background:

Malfunctions in intercellular communications can often lead to the formation of cancer cells or cell death in animals. In plants, intercellular communication mediated by plasmodesmata (Figure 1) controls physiological and developmental processes by allowing macromolecular trafficking of proteins and various kinds of RNAs between cells. The long-term goal of our research is to elucidate the molecular composition and mechanism that govern the cell-to-cell communication mediated by plasmodesmata. We believe that plasmodesmata provide a unique system to help gain fundamental insights into the molecular nature of intercellular communication in multicellular organisms. The focus of this project is to identify plasmodesmal channel protein (PCP) and to characterize its structure and function.

Figure 1. Structure of plasmodesmata. Schematic drawings of the longitudinal section (Top) and the cross section (Bottom) show adjacent cells are connected by plasmodesmata across cell wall and globular proteins (putative plasmodesmal proteins, PCPs) are embedded within the plasma membrane inner leaflet and ER outer leaflet.

Project Goals:

1. 1. Purify and identify the putative plasmodesmal channel protein, PCP. We will purify PCP1 by using plasmodesmata enrichment, chromatographic, and immunological methods, and determine its molecular identity.
2. 2. Characterize the structure and function of PCP. We will analyze the functional domains of PCP to correlate the domain structure to the protein targeting and function.
3. 3. Assess the role of PCP in macromolecular trafficking and cell-to-cell communication. We will investigate the function of PCP in plants by analyzing the loss-of-function and gain-of-function mutants. We will also identify other PCPs that form a complex or interact with PCP1.

Results:

Experimental scheme for the purification of PCP1 from Plasmodesmal-enriched cell wall proteins (PECP) is shown below. PECP extraction protocol from rice cells was developed and will be used to purify PCP1.