Fig. 5: CPK1 activates CNGC5/6/9 in HEK293T cells.

Cytosolic Ca²⁺ imaging and patch clamping analysis were performed in HEK293T cells, and the activation of CNGC5/6/9 by CPK1, but not by CPK1^D274A, was observed. CPK1, CPK1^D274A, and CNGC5/6/9 were cloned into the vector pCI-neo-IRES-YC3.6, and the vectors were then transformed into HEK293T cells using the Lipofectamine 2000 Transfection Reagent Kit individually or in a combination as indicated. HEK293T cells were cultured for 2-3 days after transformation, and the HEK293T cells with bright YC3.6 fluorescent signal were used for cytosolic Ca²⁺ imaging and patch clamping analysis. a–c Cytosolic Ca²⁺ imaging data show the activation of CNGC5 (a), CNGC6 (b), and CNGC9 (c) by CPK1, but not by CPK1^D274A (c). 10 mM external Ca²⁺ was added as indicated by the arrows. d–i Typical whole-cell recordings (d, f, and h) and average current-voltage curves (e, g, and i) of patch clamping results show the activation of CNGC5 (d and e), CNGC6 (f and g), and CNGC9 (h and i) by CPK1. C5, C6, and C9 represent CNGC5, CNGC6, and CNGC9, respectively. The numbers of HEK293T cells tested are indicated in brackets, and data are presented as means ± SEM in (a–c), (e), (g), and (i). Source data are provided as a Source Data file.