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Center for Nonlinear Studies |
In the first part of this talk, I will present a new mechanism of a Calcium-induced conformational switch, L-plastin, which plays a role in regulating migration speeds of T-cell by binding and unbinding to T-cell’s actin filaments upon the dissociation and association of Calcium ions, respectively. I use both 0.8-millisecond simulation and experimental data to show how the C-terminal tail of L-plastin (called H5 tail) regulates the binding of Calcium ions, which in turn aid L-plastin to transform from apo (calcium-free) to holo (calcium-bound) states. In the second part of the talk, I will show some evidence that might help to assess a hypothesis in the studies of RAS proteins, which are part of cellular signaling pathways. I hypothesize that the farnesyl-modified-terminal tail of RAS, called Hypervariable Region (HVR) with a high density of cation amino acids, may help to control thespecific orientation states of RAS proteins on membranes, depending on the densities and types of anion lipids. I will show that this HVR senses different densities of neighboring anion lipids to change its dynamics and to noticeably affect the overall protein to prefer specificorientation states.
Host: David Métivier