Spectrin is the major constituent of the cytoskeletal network underlying the erythrocyte plasma membrane. It associates with band 4.1 and actin to form the cytoskeletal superstructure of the erythrocyte plasma membrane. Essential for larval survival and development. Stabilizes cell to cell interactions that are critical for the maintenance of cell shape and subcellular organization within embryonic tissues. Lva and spectrin may form a Golgi-based scaffold that mediates interaction of Golgi bodies with microtubules and facilitates Golgi-derived membrane secretion required for the formation of furrows during cellularization. Native spectrin molecule is a tetramer composed of two antiparallel heterodimers joined head to head so that each end of the native molecule includes the C-terminus of the alpha subunit and the N-terminus of the beta subunit. Interacts with calmodulin in a calcium-dependent manner, interacts with F-actin and also interacts with Lva. Interacts with Ten-m. Near the inner surface of the plasma membrane of nearly all cells. Lva-alpha-spectrin complexes are found at the Golgi. A substantial pool of maternal protein in the egg undergoes dynamic changes in distribution early in embryogenesis. In gastrulated embryo, the highest level of protein is found in the respiratory tract cells and the lowest in parts of the forming gut. Expressed both maternally and zygotically. Its transcript shares the first untranslated exon with the dlt transcript, suggesting a common regulation. Belongs to the spectrin family. Truncated N-terminus.