Fig. 2.
Gi and Go activation by PufTMT- and C-terminal trunctaed MosOpn3-based pigments. The open and filled circles indicate G protein activation in the presence of the irradiated and nonirradiated pigments, respectively. (A and B) The Gi-activation efficiencies of the PufTMT- (A, blue circles) and C-terminal truncated MosOpn3 (MosOpn3ΔC)- (B, red circles) based pigment were compared with that of bovine rhodopsin (gray circles) at the same pigment concentration. The Gi activation efficiency of ∼10-fold concentration of PufTMT-based pigment is also shown (A, red circles). Note that the activity of nonirradiated PufTMT-based pigment (×1) is overlapped by that of ∼10 fold concentration of the nonirradiated pigment (red filled circles). (C and D) The Go-activation efficiencies of the PufTMT- (C, red circles) and MosOpn3ΔC- (D, red circles) based pigments were compared with that of bovine rhodopsin (gray circles) at the same pigment concentration. It should be noted that the full-length MosOpn3-based pigment exhibited virtually the same profile of G protein activation (Fig. S4), indicating that C terminus of the MosOpn3 did not markedly affect G protein selectivity.