Insulin receptor isoforms

Insulin receptor isoforms as targets

The screening platform allows to identify whether a substance (peptide, aptamer, etc.) positively or negatively affects insulin signalling via insulin receptor A (IR-A) or insulin receptor B (IR-B). Activation of IR-A versus IR-B can be detected by an increase in red versus green fluorescence, respectively.

Insulin sends signals to cells via two receptors

Insulin has many functions in the body and affects the activity of most cells. To initiate specific molecular processes in a cell, insulin binds to one of its two receptors, IR-A and IR-B, embedded in cell membrane.

Signaling via IR-A and IR-B leads to distinct molecular events

In the pancreatic beta-cell for example, binding of insulin to IR-A initiates a chain of molecular events resulting in insulin production. On the other hand, binding of insulin to IR-B increases the production of glucokinase, the glucose sensor of the beta-cell.

Different tissues have different amounts of IR-A and IR-B

Almost every cell in the body has both IR-A and IR-B embedded in its plasma membrane. Typical insulin targets tissues like fat, muscle and liver cells have predominantly IR-B. Cancer cells, on the other hand, have mostly IR-A.

Platform for screening substances that selectively inhibit or activate insulin receptors

Biocrine has developed a set of tools facilitating efficient and precise screening of compounds that selectively activate or inhibit signalling via either IR-A or IR-B. In a fluorescent microscope, activation of IR-A versus IR-B can be detected by an increase in red versus green fluorescence, respectively.

Barbara Leibiger and Ingo Leibiger