Wiring rgb strips to controller with common voltage

I have an rgb led controller that provide one wire with 5v and three wires with GRD (for R, G and B)
and I want to control with that controller over 3 led strips (again, R, G and B).
I also have power source of 12V and three N-channel MOFSETs.

I connected the wiring as described in the figure, but I have no idea how to connect the controller to the 'gate's in the MOFSETs.

thanks for helping