1AA2, 1BKR, 3EDV671120742ENSG00000115306ENSMUSG00000020315Q01082Q62261NM_003128NM_178313NM_009260NM_175836NP_003119NP_842565NP_033286NP_787030Spectrin beta chain, brain 1 is a protein that in humans is encoded by the SPTBN1 gene.

[5] Spectrin is an actin crosslinking and molecular scaffold protein that links the plasma membrane to the actin cytoskeleton, and functions in the determination of cell shape, arrangement of transmembrane proteins, and organization of organelles.

It is composed of two antiparallel dimers of alpha- and beta- subunits.

The encoded protein contains an N-terminal actin-binding domain, and 17 spectrin repeats that are involved in dimer formation.

Multiple transcript variants encoding different isoforms have been found for this gene.