Chapter 10: NMR Structures, Dynamics and Interactions of Protein Complexes in β2 Integrins

Integrins are type I transmembrane heterodimeric, α and β subunit, signal transducers. Integrins are key proteins in regulating cell adhesion and migration. Leucocyte-specific β2 integrins are comprised of four members, αLβ2, αMβ2, αXβ2 and αDβ2, which are crucial for the maintenance of immune functions. The cytosolic tail or domain of the β subunit of β2 integrins interacts with the cytosolic tail of the α subunits in the resting state of the receptors. Also, a number of soluble proteins are known to interact with the β cytosolic tail. NMR methods are providing atomic-resolution information of the structures, dynamics and binding interactions of cytosolic tails and with cognate proteins. This chapter describes an overview of various models of allosteric structural changes of integrins and applications of NMR in revealing critical structures and transient interactions of β2 integrins.