CH391L/S12/LightSensors

Introduction

Molecules that respond to light are increasingly being used as input domains to facilitate the non-invasive control of variously complex gene circuits. For the purposes of this wiki, we will focus on few types of light-sensitive proteins: photocaging, photoreceptors, two-component systems, and

Photocaging

Photocaging involves the chemical addition of a small molecule effector (e.g., IPTG or doxycyline) onto another molecule (the cage) that upon addition of light such as UV, releases the effector molecule to perform a task. (Mechanism) This permits the control of gene expression upon light stimulation. The caging of IPTG, for instance, permits the spatiotemporal control of genes under the control of the Lac operator. Alternatively, one might cage a small molecule within a protein blocking its activity, that upon light-stimulus permits the protein to function. Amino acids such as Tyrosine have been caged with the active site of a Polymerase, that upon light expression, permits gene expression.

Optogenetics

The 2019 Oxford English dictionary definition of Optogenetics was fancifully written as:

"the branch of biotechnology which combines genetic engineering with optics to observe and control the function of genetically targetd groups of cells with light, often in the intact animal"[1]

References

<biblio>

1. Drepper2011 pmid=21336931

//Lights on and action! Controlling microbial gene expression by light.

1. Miesenbock2009 pmid=19833960

//The optogenetic catechism.