An abundant phosphoprotein (864 aa) of the human erythrocyte membrane cytoskeleton which interacts with spectrin and actin. It is a member of the ERM family of proteins (which have a characteristic FERM domain) and there are multiple tissue-specific isoforms: erythrocyte 4.1 (4.1R, EPB41), a neuronal form (4.1N, EPB41L1), a general form (4.1G, EPB41L2) encoded by another gene and widely distributed; a brain form (4.1B, EPBL3, DAL1, differentially expressed in adenocarcinoma of the lung) is another variant. Brain protein 4.1 (synapsin I) is the best characterized of the nonerythroid forms of protein 4.1. Mutations in 4.1R can cause hereditary elliptocytosis.
Subjects: Medicine and Health.