Part:BBa_K2263002

Part BBa K2263002 encodes Kir2.1: an inwardly rectifying potassium channel, encoded by the kcnj2 gene.

It has been shown that Kir2.1 influences the electrophysiological properties when expressed in HEK-293 cells, resulting in a stable membrane potential of approximately -70mV, instead of the -30 to -40 mV typically found in non-transfected cells.(1)

This biobrick is a mammalian membrane protein gene, and is interesting for projects in the field of electrophysiology.

In our project, where we developed a biosensor based on electrophysiological oscillations, we used a model to predict which proteins could lead to this oscillating system. (Read more about that on our wiki: http://2017.igem.org/Team:KU_Leuven ) To verify that we could not just use any ion channel, we made an analog system using Kir2.1. As expected, this system did not result in oscillation, which demonstrated the importance of our model.

For teams that want to use this biobrick, we suggest to clone the part into a mammalian expression vector, followed by an internal ribosome entry site (IRES) and a fluorescent marker. In this case, the part and the marker are transcribed at the same time, but translated independently. In such a system, the marker indicates that the part is transcribed in the cell, but they are not physically linked. This is beneficial, as a linked marker protein may affect or hinder the protein function.

IRES sequences and fluorescent markers can be found throughout the registry. Furthermore, many labs using mammalian expression vectors will own empty vectors containing an IRES and a marker. You could clone this part directly into such a vector.

This biobrick has been provided to the registry, and has been sequenced before shipment. Naturally, when used in our project, the biobrick was cloned into a human expression vector - pIRES-dsRED. The sequence of the part has also been verified in this construct before using it in our project. If you are interested in the raw sequencing data, you can contact us via email ( igem2017@kuleuven.be ) or via social media. A blast of the sequence can be found in the following image:

(1). Zhang, DY., Lau, CP. & Li, GR. Pflugers Arch. Human Kir2.1 channel carries a transient outward potassium current with inward rectification. (2009) Eur J Physiol. 457: 1275–1285