Mechanisms Regulating Transient Receptor Potential Cation Channel A1 (TRPA1) and Their Roles in Nociception and Nociceptive Sensitization

Nociception is the sensory nervous system that detects harmful stimuli including excessive heat, cold, toxic chemicals, and noxious mechanical stimulations. Transient receptor potential (TRP) channels are a group of evolutionarily conserved ion channels consisting of 4 subunits, each with 6 transmembrane spans, and detect a variety of external and internal nociceptive stimuli. Due to their critical roles in nociception, it is essential to understand the mechanisms that regulate TRP channels and subsequent nociception. Here, I investigated two distinct types of regulation of Drosophila transient receptor potential cation channel A1 (TrpA1): regulation via the expression of different TrpA1 isoforms, and via its binding with associated proteins. I found that one of the TrpA1 isoforms, TrpA1(E), inhibits the thermal responses of other TrpA1 isoforms in vitro. I also identified potential TrpA1 binding partners through Co- immunoprecipitation (Co-IP) and mass spectrometry analysis. These binding partners need further validation and characterization through biochemical, cellular, and behavioral assays to illustrate their roles in nociception, and may serve as potential drug targets for chronic pain

Topological gauge theory, symmetry fractionalization, and classification of symmetry-enriched topological phases in three dimensions

Symmetry plays a crucial role in enriching topological phases of matter. Phases with intrinsic topological order that are symmetric are called symmetry-enriched topological phases (SET). In this paper, we focus on SETs in three spatial dimensions, where the intrinsic topological orders are described by Abelian gauge theory and the symmetry groups are also Abelian. As a series work of our previous research [Phys. Rev. B 94, 245120 (2016); (arXiv:1609.00985)], we study these topological phases described by twisted gauge theories with global symmetry and consider all possible topologically inequivalent "charge matrices". Within each equivalence class, there is a unique pattern of symmetry fractionalization on both point-like and string-like topological excitations. In this way, we classify Abelian topological order enriched by Abelian symmetry within our field-theoretic approach. To illustrate, we concretely calculate many representative examples of SETs and discuss future directions