Patent ID: 8835399

Claim:
A method for producing photoactive fusion proteins having a desired activity controllable by far-red and/or near-infrared (NIR) light, said method comprising the steps: a. designing one or more homodimeric fusion proteins, each comprising a photoreceptor protein module and a heterologous output module, wherein: i. said homodimeric fusion proteins comprise two monomers that each comprise: (1) a photoreceptor module of a bacteriophytochrome; and (2) a heterologous output module capable of being activated upon homodimerization to perform said desired activity; and ii. said monomers are not active when separated, but are capable of combining to form homodimers that are controllable by NIR light: wherein designing said fusion proteins comprises identifying candidate output domains based on 3D structures or models, identifying candidate protein fusion sites and estimating lengths of a-helices linking said output modules to said photosensory modules; b. producing a plurality of DNA molecules, each encoding a said monomer of a said homodimeric fusion protein that has at least one unique fusion site; c. screening said DNA molecules for their ability to produce homodimeric photoactive fusion proteins capable of performing said desired activity by a method comprising: i. transforming a designed non-human test organism with a plurality of different said DNA molecules such that a different said fusion protein is expressed in each test organism; ii. allowing the expressed fusion proteins to bind bacteriophytochrome chromophore and form homodimeric proteins; and iii. applying selected wavelengths of NIR light to said transformed organisms and determining the level of said desired activity of said fusion proteins in said organisms in the presence and absence of said selected wavelengths of light; wherein the level of said desired activity of said fusion proteins is controllable by NIR light when the level of said desired activity is changed by the presence and/or absence of MR light having said selected wavelengths.