Spectrin, beta subunit (IPR016343)

Short name: Spectrin_bsu

Overlapping homologous superfamilies


Family relationships



Spectrins are involved in the support of general membrane integrity, stabilisation of cell-cell interactions, axonal growth, normal functioning of the Golgi complex and organisation of synaptic vesicles [PMID: 10917516, PMID: 10852813, PMID: 12149647]. Spectrin is a tetrameric actin cross-linking protein, which contains two alpha and two beta subunits. Two genes for alpha-spectrin [PMID: 7757495, PMID: 9593709, PMID: 12149647] and five for beta-spectrin have been identified in both mice and humans, each of which is alternatively spliced to produce multiple spectrin isoforms [PMID: 9075575, PMID: 7757495]. Beta-spectrins are more diverse than alpha-spectrin, and include mammalian erythrocytic beta-spectrin, non-erythroid beta-spectrin/Fodrin (beta-G, the general form of beta-spectrin expressed in multiple tissues), a novel beta-G spectrin (ELF1-4) that lacks the C-terminal PH (pleckstrin homology) domain, the brain-specific SPTBN2, and beta-V spectrin.

ELF (Q62261), a modulator of the Smad adaptor proteins involved in the TGF-beta signalling pathway, was originally identified from endodermal stem/progenitor cells committed to foregut lineage [PMID: 12543979, PMID: 10615055]. ELF is a beta-spectrin that is important for distinct functional membrane generation, protein sorting, cell adhesion and the development of a polarized differentiated epithelial cell [PMID: 10852813, PMID: 16359909]. ELF-deficient mice display disruption of transforming growth factor-beta (TGF-beta) signalling by Smad proteins [PMID: 12543979]. Evidence from null mutants of ELF confirms that ELF is a novel beta-G spectrin and not an isoform of beta-spectrins [PMID: 12149647]. Aberrations in Elf's involvement in Smad4 localization and subsequent activation of Smad4 could result in tumourigenesis.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0003779 actin binding
GO:0005200 structural constituent of cytoskeleton

Cellular Component

GO:0008091 spectrin

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.