Modulation of voltage-gated Ca2.2 Ca channels by newly identified interaction partners.

Voltage-gated Ca channels are typically integrated in a complex network of protein-protein-interactions, also referred to as Ca channel nanodomains. Amongst the neuronal Ca2 channel family, Ca2.2 is of particular importance due to its general role for signal transmission from the periphery to the central nervous system, but also due to its significance for pain perception. Thus, Ca2.2 is an ideal target candidate to search for pharmacological inhibitors but also for novel modulatory interactors. In this review we summarize the last years findings of our intense screenings and characterization of the six Ca2.2 interaction partners, tetraspanin-13 (TSPAN-13), reticulon 1 (RTN1), member 1 of solute carrier family 38 (SLC38), prostaglandin D2 synthase (PTGDS), transmembrane protein 223 (TMEM223), and transmembrane BAX inhibitor motif 3 (Grina/TMBIM3) containing protein. Each protein shows a unique way of channel modulation as shown by extensive electrophysiological studies. Amongst the newly identified interactors, Grina/TMBIM3 is most striking due to its modulatory effect which is rather comparable to G-protein regulation.