Topic: Tusc5

We have recently identified Tusc5 as a Retinal Ganglion Cell (RGC) marker, specifically expressed in Brn3a+ RGCs, and absent from Brn3aKO retinas. Tusc5 is a transmembrane protein that assists trafficking of Glucose transporter GluT4 in adipocites. GluT4 are continuously recycled through endosomes from and to the plasma membrane and stored in GSVs (Glut4 Storage Vesicles), in an insulin-dependent manner. In adipocites, GluT4 recycling is assisted by Tusc5. In mouse retina, Tusc5 is expressed specifically in a subset of Brn3a+ retinal ganglion cells (RGCs), characterized by small dense “bushy”

Dorsal root ganglion (DRG) neurons are quintessential for peripheral pain transduction, a process mediated, among others, by certain members of the transient receptor potential (TRP) superfamily of ion channels. Among those, TRPA1, TRPV1, TRPM3 and TRPM8 have been linked to chronic pain and neuropathies. Tumor suppressor candidate 5 (Tusc5) plays a role in adipocyte function, but is also expressed in all major classes of DRG neurons. Tusc5 function in DRGs has not been investigated. We conducted Fura-2 calcium imaging and patch clamp experiments in cultured DRG neurons from knock-in Tusc5eGFP

Tusc5 is a transmembrane protein that assists trafficking of Glucose transporters molecules in adipocites. We and others have previously described Tusc5 in projection sensory neurons. Glut4 transporters (localized in muscles and adipocytes) are continuously recycled through endosomes from and to the plasma membrane and stored in GSVs (Glut4 Storage Vesicles). In adipocites, Tusc5 follows Glut4 trafficking between GSVs and cell surface, upon insulin stimulation. Tusc5 interacts with the signaling cascade of fusion of GSVs with the plasma membrane, similar to the exocytosis mechanism in neuronal