Light-activated chimeric opsins and methods of using the same
Provided herein are compositions comprising light-activated chimeric proteins expressed on plasma membranes and methods of using the same to selectively depolarize excitatory or inhibitory neurons.
1. An isolated light-responsive chimeric polypeptide comprising an amino acid sequence having at least 95% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:1.
2. The chimeric polypeptide of claim 1 , wherein the polypeptide is activated by light of a wavelength between about 540 nm to about 560 nm.
3. The chimeric polypeptide of claim 1 , further comprising a C-terminal trafficking signal.
4. The chimeric polypeptide of claim 3 , wherein the trafficking signal comprises the amino acid sequence KSRITSEGEYIPLDQIDINV (SEQ ID NO:15).
5. The chimeric polypeptide of claim 1 , wherein the light-responsive chimeric polypeptide comprises an amino acid sequence having at least 98% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:1.
6. The chimeric polypeptide of claim 1 , wherein the polypeptide comprises a Glu to Thr amino acid substitution at position 122 relative to the amino acid sequence set forth in SEQ ID NO:1.
7. The chimeric polypeptide of claim 1 , wherein the polypeptide comprises a Glu to Thr amino acid substitution at position 162 relative to the amino acid sequence set forth in SEQ ID NO:1.
8. The chimeric polypeptide of claim 1 , wherein the polypeptide comprises a Glu to Thr amino acid substitution at position 122 and a Glu to Thr amino acid substitution at position 162 relative to the amino acid sequence set forth in SEQ ID NO:1.
9. The chimeric polypeptide of claim 1 , wherein the light-responsive chimeric polypeptide comprises an amino acid sequence having at least 99% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:1.
10. An isolated polynucleotide comprising a nucleotide sequence encoding a light-responsive chimeric polypeptide comprising an amino acid sequence having at least 95% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:1.
11. The isolated polynucleotide of claim 10 , wherein the nucleotide sequence is operably linked to a promoter.
12. The polynucleotide of claim 10 , wherein the polynucleotide is an expression vector.
13. The polynucleotide of claim 12 , wherein the expression vector is a viral vector.
14. The isolated polynucleotide of claim 10 , wherein the light-responsive chimeric polypeptide comprises an amino acid sequence having at least 98% amino acid sequence identity to the amino acid sequence set forth in SEQ ID NO:1.
15. The isolated polynucleotide of claim 10 , wherein the light-responsive chimeric polypeptide further comprises a C-terminal trafficking signal.
16. The isolated polynucleotide of claim 15 , wherein the trafficking signal comprises the amino acid sequence KSRITSEGEYIPLDQIDINV (SEQ ID NO:15).
17. The isolated polynucleotide of claim 10 , wherein the light-responsive chimeric polypeptide comprises a Glu to Thr amino acid substitution at position 122 relative to the amino acid sequence set forth in SEQ ID NO:1.
18. The isolated polynucleotide of claim 10 , wherein the light-responsive chimeric polypeptide comprises a Glu to Thr amino acid substitution at position 162 relative to the amino acid sequence set forth in SEQ ID NO:1.
19. The isolated polynucleotide of claim 10 , wherein the light-responsive chimeric polypeptide comprises a Glu to Thr amino acid substitution at position 122 and a Glu to Thr amino acid substitution at position 162 relative to the amino acid sequence set forth in SEQ ID NO:1.