Light-Activated Proton Pumps and Applications Thereof
In a method for adjusting the voltage potential or pH of, or cause proton release from, cells, subcellular regions, or extracellular regions, a gene encoding for a light-driven proton pump is incorporated into at least one target cell or region, the proton pump operating in response to a specific wavelength of light. Expression of the gene is caused by exposing the target cell or region to the specific wavelength of light in a manner designed to cause the voltage potential adjustment, pH adjustment, or proton release. The proton pump may be a microbial rhodopsin, in particular derived from the halorubrum genus of archaeabacteria, or be derived from leptosphaeria maculans, P. triticirepentis , and S. scelorotorium . The voltage potential of the target cell or region may adjusted until it is hyperpolarized in order to achieve neural silencing. Light-activated proton pumps responsive to different wavelengths of light may be used together to achieve multi-color neural silencing.
1 . A method for adjusting the voltage potential of cells, subcellular regions, or extracellular regions, the method comprising:
incorporating at least one gene encoding for a light-driven proton pump into at least one target cell, subcellular region, or extracellular region, the proton pump operating to change transmembrane potential in response to a specific wavelength of light; and
causing the expression of the gene by exposing the target cell, subcellular region, or extracellular region to the specific wavelength of light in a manner designed to cause the voltage potential of the target cell, subcellular region, or extracellular region to increase or decrease.
2 . The method of claim 1 , wherein the proton pump is a microbial rhodopsin that is outwardly rectifying.
3 . The method of claim 1 , wherein the proton pump is derived from the halorubrum genus of archaeabacteria.
4 . The method of claim 3 , wherein the proton pump is derived from an organism selected from the group consisting of halorubum strain aus-1 , halorubrum strain aus-2 , halorubrum sodomense, halorubrum strain BD1 , halorubrum strain xz515 , halorubrum strain TP009, and halorubrum lacusprofundi.
5 . The method of claim 1 , wherein the proton pump is derived from an organism selected from the group consisting of leptosphaeria maculans, P. triticirepentis , and S. scelorotorium.
6 . The method of claim 1 , further comprising the step of increasing or decreasing the voltage potential of the target cell, subcellular region, or extracellular region until it is hyperpolarized.
7 . The method of claim 6 , wherein the target cell, subcellular region, or extracellular region is a neuron and the hyperpolarization achieves neural silencing.
8 . The method of claim 7 , further comprising the step of using a plurality of light-activated proton pumps responsive to different wavelengths of light to achieve multi-color neural silencing by the steps of:
expressing each light-activated proton pump in a different population of cells; and
illuminating the cells with different colors of light.
9 . The method of claim 2 , wherein the microbial rhodopsin is both inwardly and outwardly rectifying at two different wavelengths of light.
10 . A method for adjusting the pH of cells, subcellular regions, or extracellular regions, the method comprising:
incorporating at least one gene encoding for a light-driven proton pump into at least one target cell, subcellular region, or extracellular region, the proton pump operating to change cell, subcellular region, or extracellular region pH in response to a specific wavelength of light; and
causing the expression of the gene by exposing the target cell, subcellular region, or extracellular region to the specific wavelength of light in a manner designed to cause the pH of the target cell, subcellular region, or extracellular region to increase or decrease.
11 . The method of claim 10 , wherein the proton pump is a microbial rhodopsin that is outwardly rectifying.
12 . The method of claim 10 , wherein the proton pump is derived from the halorubrum genus of archaeabacteria.
13 . The method of claim 12 , wherein the proton pump is derived from an organism selected from the group consisting of halorubum strain aus-1 , halorubrum strain aus-2 , halorubrum sodomense, halorubrum strain BD1 , halorubrum strain xz515 , halorubrum strain TP009, and halorubrum lacusprofundi.
14 . The method of claim 10 , wherein the proton pump is derived from an organism selected from the group consisting of leptosphaeria maculans, P. triticirepentis , and S. scelorotorium.
15 . The method of claim 11 , wherein the microbial rhodopsin is both inwardly and outwardly rectifying at two different wavelengths of light.
16 . A method for causing cells, subcellular regions, or extracellular regions to release protons as chemical transmitters, the method comprising:
incorporating at least one gene encoding for a light-driven proton pump into at least one target cell, subcellular region, or extracellular region, the proton pump operating to cause proton release in response to a specific wavelength of light; and
causing the expression of the gene by exposing the target cell, subcellular region, or extracellular region to the specific wavelength of light in a manner designed to cause the target cell, subcellular region, or extracellular region to release protons.
17 . The method of claim 16 , wherein the proton pump is a microbial rhodopsin that is outwardly rectifying.
18 . The method of claim 16 , wherein the proton pump is derived from the halorubrum genus of archaeabacteria.
19 . The method of claim 18 , wherein the proton pump is derived from an organism selected from the group consisting of halorubum strain aus-1 , halorubrum strain aus-2 , halorubrum sodomense, halorubrum strain BD1 , halorubrum strain xz515 , halorubrum strain TP009, and halorubrum lacusprofundi.
20 . The method of claim 16 , wherein the proton pump is derived from an organism selected from the group consisting of leptosphaeria maculans, P. triticirepentis , and S. scelorotorium.