Spectrin Beta, Non Erythrocytic 1 (SPTbN1)

SPTbN1 is one member of a family of beta-spectrin genes. The encoded protein contains an N-terminal actin-binding domain, and 17 spectrin repeats which are involved in dimer formation. Multiple transcript variants encoding different isoforms have been found for this gene.The deduced 2,364-amino acid SPTBN1 protein has a calculated molecular mass of 274.5 kD. Like SPTB, SPTBN1 has a putative N-terminal actin-binding domain, a central tandem series of 17 repeats of a 106-amino acid motif, and a C-terminal domain. Northern blot analysis of several rat tissues detected highest expression in lung, followed by kidney, brain, thymus, heart, and liver. Western blot analysis of cytosolic and membrane fractions of rat tissues revealed Sptbn1 proteins of 275 to 285 kD that were enriched in membrane fractions of brain, kidney, and lung.