Linking integrin conformation to function.
Integrins are alphabeta heterodimeric adhesion receptors that relay signals bidirectionally across the plasma membrane between the extracellular matrix and cell-surface ligands, and cytoskeletal and signalling effectors. The physical and chemical signals that are controlled by integrins are essential for intercellular communication and underpin all aspects of metazoan existence. To mediate such diverse functions, integrins exhibit structural diversity, flexibility and dynamism. Conformational changes, as opposed to surface expression or clustering, are central to the regulation of receptor function. In recent years, there has been intense interest in determining the three-dimensional structure of integrins, and analysing the shape changes that underpin the interconversion between functional states. Considering the central importance of the integrin signalling nexus, it is perhaps no surprise that obtaining this information has been difficult, and the answers gained so far have been complicated. In this Commentary, we pose some of the key remaining questions that surround integrin structure-function relationships and review the evidence that supports the current models.
Askari
Janet A
JA
Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK.
Buckley
Patrick A
PA
Mould
A Paul
AP
Humphries
Martin J
MJ
D000818:Animals; D001665:Binding Sites; D002448:Cell Adhesion / Q000502:physiology; D002450:Cell Communication / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D003599:Cytoskeleton / Q000502:physiology; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D039001:Integrin alpha Chains / Q000737:chemistry* / Q000378:metabolism; D039641:Integrin beta Chains / Q000737:chemistry* / Q000378:metabolism; D008024:Ligands; D017434:Protein Structure, Tertiary / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D016608:Talin / Q000378:metabolism*
D003598:Cytoskeletal Proteins; D039001:Integrin alpha Chains; D039641:Integrin beta Chains; D008024:Ligands; D016608:Talin