FunctionSerine protease inhibitor that inhibits plasminogen activators and plasmin but not thrombin. May be involved in the formation or reorganization of synaptic connections as well as for synaptic plasticity in the adult nervous system. May protect neurons from cell damage by tissue-type plasminogen activator.
Tissue specificityPredominantly expressed in the brain.
Involvement in diseaseDefects in SERPINI1 are the cause of familial encephalopathy with neuroserpin inclusion bodies (FEN1B) [MIM:604218]. FEN1B is characterized clinically as an autosomal dominantly inherited dementia, histologically by unique neuronal inclusion bodies and biochemically by polymers of neuroserpin.
Sequence similaritiesBelongs to the serpin family.