Small actin bundling proteins that are highly enriched in the microvilli of certain chemosensory and mechanosensory cells, often with other actin bundling proteins. Various isoforms generated by alternative splicing occur in a tissue-specific manner and range in size from 854 aa to 322 aa. They cause elongation of actin bundles and thus help determine the steady-state length of microvilli and stereocilia. Espins bind actin monomer via their WH2 domain and some isoforms can also bind phosphatidylinositol 4,5-bisphosphate, profilins, or SH3 proteins. Mutations in espin are associated with DFNB36 (autosomal recessive neurosensory deafness 36).
Subjects: Medicine and Health.