Devices, systems and methods for optogenetic modulation of action potentials in target cells
Aspects of the disclosure include devices, systems and methods for optogenetic modulation of action potentials in target cells. The subject devices include light-generating devices, control devices, and delivery devices for delivering vectors to target cells. The subject systems include light-activated proteins, response proteins, nucleic acids comprising nucleotide sequences encoding these proteins, as well as expression systems that facilitate expression of these proteins in target cells. Also provided are methods of using the subject devices and systems to optogenetically inhibit and intercept action potentials in target cells, e.g., to treat a neurological or psychiatric condition in a human or non-human animal subject.
1. A method for modulating the membrane potential of a mammalian cell in response to light, the method comprising exposing the cell to the light, wherein the cell is genetically modified with a nucleic acid comprising a nucleotide sequence encoding a fusion polypeptide comprising:
a) a light-activated proton pump protein comprising an amino acid sequence having at least 90% homology to one of the amino acid sequences of SEQ ID NOs: 1, 4, 5, and 6; and
b) an acid-sensitive ion channel, wherein the acid-sensitive ion channel comprises an amino acid sequence having at least 80% homology to the ASIC2a polypeptide amino acid sequence of SEQ ID NO: 19, wherein the nucleotide sequence is operably linked to a promoter, and wherein exposure of the cell to the light activates the light-activated proton pump protein, wherein activation of the light-activated proton pump protein activates the acid-sensitive ion channel and thereby modulates the membrane potential of the cell.
2. The method of claim 1 , wherein the acid-sensitive ion channel amino acid sequence has at least 90% homology to the amino acid sequence of SEQ ID NO: 19.
3. The method of claim 1 , wherein the light-activated proton pump protein amino acid sequence has at least 95% homology to the amino acid sequence of any one of SEQ ID NOs: 1, 4, 5, and 6 , 16, and 62.
4. The method of claim 1 , wherein the fusion polypeptide comprises a membrane trafficking signal.
5. The method of claim 4 , wherein the membrane trafficking signal comprises the amino acid sequence KSRITSEGEYIPLDQIDINV (SEQ ID NO:37).
6. The method of claim 1 , wherein the promoter is a neuron-specific promoter.
7. The method of claim 1 , wherein the cell is a neuron.
8. The method of claim 1 , wherein the fusion polypeptide comprises an endoplasmic reticulum (ER) export signal.
9. The method of claim 8 , wherein the ER export signal comprises the amino acid sequence FCYENEV (SEQ ID NO:47).
10. The method of claim 1 , wherein the light-activated proton pump protein amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:1.
11. The method of claim 1 , wherein the light-activated proton pump protein amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:4.
12. The method of claim 1 , wherein the light-activated proton pump protein amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:5.
13. The method of claim 1 , wherein the light-activated proton pump protein amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:6.
14. The method of claim 1 , wherein the acid-sensitive ion channel amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:19.
15. The method of claim 1 , wherein the fusion polypeptide amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:31.
16. The method of claim 1 , wherein the fusion polypeptide amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:32.
17. The method of claim 1 , wherein the fusion polypeptide amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:33.
18. The method of claim 1 , wherein the fusion polypeptide amino acid sequence has at least 95% homology to the amino acid sequence of SEQ ID NO:34.