Schematic representation of 4.1R complementary DNA (cDNA) and functional domains.

The 17 nucleotides (NTs) at the 5′ end of exon 2 and exon 14, 15, 17a, and 17b sequences are absent from the erythroid mRNA isoform. Functional domains deduced from limited chymotryptic digestion are shown at the bottom of the cDNA depiction. The 4.1R interacts with many membrane or intracellular components. Some of these interactions (asterisks) were found in nonerythroid cells. PS indicates phosphatidylserine; and CaM, calmodulin. ▨, constitutive coding sequences; , alternative coding sequences; ⊠, alternative non-coding sequence; □, untranslated regions.