SPTBN1

Spectrin beta chain, brain 1 is a is_associated_with::protein that in humans is encoded by the SPTBN1 is_associated_with::gene.

Function
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. This gene is one member of a family of beta-spectrin genes. 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.

Interactions
SPTBN1 has been shown to interact with Merlin.

Model organisms
is_associated_with::Model organisms have been used in the study of spectrin function. A conditional is_associated_with::knockout mouse line, called Spnb2tm1a(EUCOMM)Wtsi was generated as part of the is_associated_with::International Knockout Mouse Consortium program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists.

Male and female animals underwent a standardized is_associated_with::phenotypic screen to determine the effects of deletion. Twenty seven tests were carried out on is_associated_with::mutant mice and four significant abnormalities were observed. Few is_associated_with::homozygous is_associated_with::mutant embryos were identified during gestation and those that were present displayed oedema. None survived until is_associated_with::weaning. The remaining tests were carried out on is_associated_with::heterozygous mutant adult mice. These animals had a decreased length of long bones, while males also displayed is_associated_with::hypoalbuminemia.