Padmini Rangamani
University of California-San Diego, CA·Biophysics
Cells constantly reshape their outer membranes. They fold them inward to swallow material, push them outward to release small packages, and stretch them into long, thin cables in neurons.
- Fields
Biophysics
Biomedical Engineering
Neuroscience
- Topics
membrane curvature
endocytosis
extracellular vesicles
- Grants
- 4 known grants, through Apr 2031
What they work on
- Model how lipid and protein asymmetry across the plasma membrane sets whether it buds inward (endocytosis, the uptake of outside cargo) or outward (extracellular vesicles), producing predictions for partner labs to test experimentally.
- Determine how attachment to the actin cytoskeleton, the cell's internal filament scaffold, generates or releases force for inward and outward budding, using computational models of membrane mechanics.
- Test computationally how the glycocalyx, the sugar-rich coat on the cell surface, changes the direction of membrane bending.
- Determine how lipid composition and cytoskeletal structure control 'pearls-on-a-string' axon shape, the placement of sodium and potassium channels, and action potential firing, combining biophysical modeling with ultrastructural imaging.
- Measure how axon shape and channel placement change with plasticity, the adjustments that follow repetitive neuronal firing, and predict the effects on neuronal output.
- Test whether liquid-like protein droplets bend membranes or bundle cytoskeletal filaments when they spread onto these surfaces, using experimentally constrained mathematical models validated by direct observation.
More about the research
These shape changes rest on simple physics: forces, tension and bending stiffness acting on a thin, fatty sheet. When the shapes go wrong, the results include cancer, inflammation, heart disease and brain disorders. The lab builds mathematical and computer models of how membranes bend. It tests the predictions with experimental partners. The projects range from single budding events at the cell surface, to protein droplets that push on membranes and filaments, to the shape and electrical signalling of nerve fibers. A newer project, whose title points to links between reactive oxygen species (ROS, chemically reactive forms of oxygen), mitochondria (the cell's power plants) and calcium in neuronal function, has no published summary yet.
Why it matters
Faulty endocytosis and vesicle release are linked to inflammation, cancer, neurodegeneration and heart disease. Changes in axon membrane mechanics are linked to epilepsy and depression. Models that predict how membranes bend could support faster design and testing of treatment strategies and nanotherapeutics. They could also help predict how axon shape or the saltiness of brain fluid alters neuronal signalling. The droplet work may clarify how pathogens enter cells and how cells move.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
John Straub
Boston University, MA·Biophysics
Identify factors that govern liquid-liquid phase separation and later amyloid aggregation of the disordered proteins tau and alpha-synuclein, combining experiments with computer simulations.
Dimitrios Vavylonis
Lehigh University, PA·Biophysics
Model how fission yeast nodes — membrane protein clusters that time cell cycle progression and cytokinesis — assemble at the nanoscale, focusing on interactions of Cdc15, Mid1 and Cdr2 with each other and with the membrane.
Priya R. Banerjee
University at Buffalo, NY·Biophysics·Early-career
Test whether pioneer transcription factors, proteins that can bind DNA packed into closed chromatin, act by forming liquid-like droplets on DNA that concentrate RNA polymerases and nucleosome-remodeling complexes to switch genes on.
The school
University of California-San Diego: 84 labs on PI Pages, $1.9B a year on research, 637 research doctorates a year.
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