GLOSSARY

The insulin receptor is a membrane protein of the receptor tyrosine kinase family that carries the insulin signal into the cell. It is present on almost all cells, but is most dense in the liver, muscle and adipose tissue.

Structure

The receptor is made of two α subunits (outside the cell, where insulin binds) and two β subunits (spanning the membrane, with kinase activity), joined by disulphide bonds as an α₂β₂ complex. This structure closely resembles the IGF-1 receptor.

Signalling Pathway