Periodic Reporting for period 3 - DIRNDL (Directions in Development)
Reporting period: 2022-09-01 to 2024-02-29
Most cells are organised in space. To function properly, cells often have distinct domains exposed to for example the outer and inner surfaces. This organization in space is referred to as cell polarity, and is a widespread property across kingdoms. In multicellular organisms, polarity domains are often aligned with organismal (front/back, outer/inner, left/right, etc) axes. Furthermore, important decisions, such as the orientation of cell division, are coupled to cell polarity. As such, cell polarity is a fundamental principle connected to normal development and disease. While cell polarity has been studied in substantial detail in single-celled yeasts and in animal models, knowledge is much more limited in the plant kingdom. From genomic analyses, it appears that plants, yeasts and animals do not share proteins in cell polarity pathways, and therefore it is largely unknown whether there are common or distinct molecular mechanisms that drive cell polarisation.
The DIRNDL project builds on recent findings by the principal investigator's team that 1) established the tools for using the early plant embryo as a model system for genetically investigating the establishment of cell polarity in the plant kingdom; 2) offer a set of novel polarity proteins in plants that allow for a proteomics strategy to map the polar proteome and 3) identified a deep protein homology of a shared structural domain that mediates protein polarity across animal and plant kingdoms. The DIRNDL project takes an integrated approach to genetically, proteomically and mechanistically dissect cell polarisation in plants (Arabidopsis and Marchantia).
The DIRNDL project builds on recent findings by the principal investigator's team that 1) established the tools for using the early plant embryo as a model system for genetically investigating the establishment of cell polarity in the plant kingdom; 2) offer a set of novel polarity proteins in plants that allow for a proteomics strategy to map the polar proteome and 3) identified a deep protein homology of a shared structural domain that mediates protein polarity across animal and plant kingdoms. The DIRNDL project takes an integrated approach to genetically, proteomically and mechanistically dissect cell polarisation in plants (Arabidopsis and Marchantia).
Whilst being obstructed by Covid-19, the DIRNDL team has made significant strides in achieving the project goals. Halfway through the project period, all approaches have been optimised, and promising discoveries are being made. In each strand of the project (genetic, proteomic, mechanistic), substantial initial data has been collected. This has already led to the identification of a deeply conserved set of plant polarity proteins, that appear to act as a protein interaction module. The further functional and genetic analysis of this module in the next phase will tell if these form part of the elude generic plant cell polarity system.
In the remaining leg of the project, we expect to achieve many of the goals set at the beginning. We expect to:
1) Characterise the biological role of the plant SOSEKI proteins through genetic and biochemical analysis
2) Identify a set of Arabidopsis genes that are critical for viability and cell polarity, as well as insight into their mode of action
3) Exhaustively map the protein composition of polar domains in plant cells and identify key regulators of cell polarity
4) Reconstitute parts of the polarity system in minimal systems (either live cells or liposomes)
1) Characterise the biological role of the plant SOSEKI proteins through genetic and biochemical analysis
2) Identify a set of Arabidopsis genes that are critical for viability and cell polarity, as well as insight into their mode of action
3) Exhaustively map the protein composition of polar domains in plant cells and identify key regulators of cell polarity
4) Reconstitute parts of the polarity system in minimal systems (either live cells or liposomes)