All organisms must sense and respond to mechanical forces generated outside the cell (shear force, gravity, touch) as well as inside the cell (osmotic pressure, membrane deformation). The Haswell lab is interested in how physical force is converted into a biochemical signal capable of altering the state of a cell. We are addressing this question in the model plant Arabidopsis thaliana where a number of important mechanical signal transduction pathways have been characterized. We use an array of biochemical and molecular genetic approaches, electrophysiology, and state-of-the-art live imaging methodologies in our experiments.

Three main lines of inquiry in the lab are: 1) functional characterization of a family of mechanosensitive ion channels related to the bacterial channel MscS; 2) genetic approaches to identifying new components of gravity and touch signal transduction pathways; and 3) investigation into the role played by mechanosensory systems in organelle shape and size determination.

• Personal/Lab Page
  

• Selected Publications

(A) Plastids from a plant expressing mutant mechanosensitive ion channels have an unusual spherical morphology (the normal football-shaped plastid found in a wild-type plant is shown in the inset). Plastids are plant-specific organelles responsible for photosynthesis, gravity response, and a number of important metabolic reactions. (B) Versions of these channels fused to Green Fluorescent Protein localize in clusters (shown in green) at the poles of the plastids. We would like to know why mechanosensitive channels are clustered at the plastid poles, and how they contribute to plastid shape and size.