Adjustable threshold switch
AssigneeCellicon Technologies, Inc.
InventorsTimothy Gardner, James J. Collins
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Abstract
Provided are methods and compositions for regulating gene expression in a cell. The invention provides recombinant adjustable-threshold switches which contain a first inducible promoter-regulatory gene operon and a second constitutive promoter-regulatory gene operon. A threshold amount of activating agent is required to switch the inducible promoter “on” and the constitutive promoter “off”. An adjustable-threshold switch is useful to reversibly switch the expression of a gene of interest between a stable “on” state and stable “off” state in response to an activating agent at or above a threshold concentration.
Claims28
A recombinant adjustable threshold genetic switch comprising:
- (a) a first nucleic acid construct comprising an inducible promoter operably associated with a first gene encoding a first repressor protein;
- and
- (b) a second nucleic acid construct comprising a constitutive promoter operably associated with a second gene encoding a second repressor protein,
- wherein the first repressor protein, when produced, is capable of repressing transcription from the constitutive promoter, and wherein transcription of the first gene encoding the first repressor protein is inducible by an activating agent, and
- wherein the second repressor protein, when produced, is capable of repressing transcription from the inducible promoter.
A method of alternating transcription from first and second promoters in a host cell, the method comprising the steps of:
- (i) providing a host cell harboring a recombinant adjustable-threshold genetic switch comprising:
- (a) a first nucleic acid construct comprising an inducible promoter operably associated with a first gene encoding a first repressor protein;
- and
- (b) a second nucleic acid construct comprising a constitutive promoter operably associated with a second gene encoding a second repressor protein,
- wherein the first repressor protein, when produced, is capable of repressing transcription from the constitutive promoter, and wherein transcription of the first gene encoding the first repressor protein is inducible by an activating agent, and
- wherein the second repressor protein, when produced, is capable of repressing transcription from the inducible promoter;
- and
- (ii) exposing the host cell to an activating agent in an amount sufficient to increase transcription of the first gene encoding the first repressor protein.
Dependencies are inferred from the claim text.