Emerging evidence for kindlin oligomerization and its role in regulating kindlin function

Integrin-mediated cell-extracellular matrix (ECM) interactions play crucial roles in a broad range of physiological and pathological processes. Kindlins are important positive regulators of integrin activation. The FERM-domain-containing kindlin family comprises three members, kindlin-1, kindlin-2 and kindlin-3 (also known as FERMT1, FERMT2 and FERMT3), which share high sequence similarity (identity >50%), as well as domain organization, but exhibit diverse tissue-specific expression patterns and cellular functions. Given the significance of kindlins, analysis of their atomic structures has been an attractive field for decades. Recently, the structures of kindlin and its β-integrin-bound form have been obtained, which greatly advance our understanding of the molecular functions that involve kindlins. In particular, emerging evidence indicates that oligomerization of kindlins might affect their integrin binding and focal adhesion localization, positively or negatively. In this Review, we presented an update on the recent progress of obtaining kindlin structures, and discuss the implication for integrin activation based on kindlin oligomerization, as well as the possible regulation of this process. Ministry of Education (MOE) Ministry of Health (MOH) National Research Foundation (NRF) Published version Our work in this area was supported by the Tier II grants MOE2017-T2-1-106 (Y.-G.G.) and MOE2016-T2-1-021 (S.-M.T.) from the Ministry of Education - Singapore (MOE). This research was also supported by the National Research Foundation Singapore under its Open Fund - Individual Research Grant (MOH000218) (S.-M.T.) and administered by the Singapore Ministry of Health’s National Medical Research Council.