Spectrin beta chain, non-erythrocytic 1 (SPTBN1)
The protein contains 2364 amino acids for an estimated molecular weight of 274609 Da.
Fodrin, which seems to be involved in secretion, interacts with calmodulin in a calcium-dependent manner and is thus candidate for the calcium-dependent movement of the cytoskeleton at the membrane. (updated: March 4, 2015)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
This protein is annotated as membranous in UniProt.
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| Variant | Description |
|---|---|
| dbSNP:rs1052790 |
Biological Process
Actin filament capping
Axon guidance
Common-partner SMAD protein phosphorylation
Endoplasmic reticulum to Golgi vesicle-mediated transport
Golgi to plasma membrane protein transport
MAPK cascade
Membrane assembly
Mitotic cytokinesis
Plasma membrane organization
Positive regulation of interleukin-2 production
Positive regulation of interleukin-2 secretion
Positive regulation of protein localization to plasma membrane
Protein localization to plasma membrane
Protein targeting to plasma membrane
Regulation of protein localization to plasma membrane
Regulation of SMAD protein signal transduction
SMAD protein import into nucleus
The reference OMIM entry for this protein is 182790
Spectrin, beta, nonerythrocytic, 1; sptbn1
Spectrin, nonerythroid, beta subunit; sptb2
Beta-spectrin, general form
Beta-g spectrin
Fodrin, beta
Embryonic liver beta-fodrin; elf
Spectrin, beta-ii
DESCRIPTION
Spectrin is a tetrameric cytoskeletal protein essential for determination of cell shape, resilience of membranes to mechanical stress, positioning of transmembrane proteins, and organization of organelles and molecular traffic. Alpha- and beta-spectrin subunits form antiparallel dimers that self associate to give the spectrin tetramer. Beta subunits, such as SPTBN1, contain most of the spectrin binding activity (Hayes et al., 2000).CLONING
Immunochemical studies demonstrate the existence of beta-spectrin-like polypeptides in nonerythroid tissues. Watkins et al. (1988) obtained a genomic clone for nonerythroid beta-spectrin by screening a DNA library with a synthetic oligonucleotide probe corresponding to human erythroid beta-spectrin (182870) cDNA. The genomic clone showed 76% homology to the erythroid beta-spectrin cDNA when translated to amino acid sequence. By screening a human brainstem expression library with bovine alpha-spectrin, followed by screening a human hippocampus cDNA library, Hu et al. (1992) cloned SPTBN1, which they designated 'general form of beta-spectrin,' or beta-G spectrin, to distinguish it from erythrocyte beta-spectrin, or beta-R spectrin (SPTB). 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. Chang et al. (1993) found that the genomic DNA for human brain beta-fodrin contained regions that cross-hybridized with an erythroid beta-spectrin cDNA probe and that the DNA sequence of these regions showed a high degree of identity and a similar exon/intron organization. Mishra et al. (1999) cloned 3 isoforms of mouse beta-spectrin, which they called Elf for 'embryonic liver beta-fodrin.' The longest isoform, Elf3, comprises 2,154 residues and is characterized by an actin-binding domain, a long repeat domain, and a short regulatory domain remarkable for the absence of a PH domain. Northern blot analysis demonstrated an abundant 9.0-kb Elf3 transcript in brain, liver, and heart tissues. Immunohistochemical studies demonstrated Elf labeling of the basolateral or sinusoidal membrane surface, as well as a granular cytoplasmic pattern in hepatocytes. Mishra et al. (1999) demonstrated that Elf3 plays a vital role in hepatocyte differentiation and intrahepatic bile duct formation. By database analysis and PCR of a skeletal muscle cDNA library, Hayes et al. (2000) cloned 2 partial SPTBN1 3-prime splice variants, which they designated sigma-1 and sigma-2. The sigma-1 variant is identical to the 3-prime sequence of the SPTBN1 cDNA cloned by Hu et al. (1992). The sigma-2 variant encodes a protein with a shorter C terminus that lacks the pleckstrin homology domain of the longer isoform and has 28 unique C-terminal residues. Antibodies raised to the short C terminus detected 240-kD proteins in rat cardiac and skeletal muscle and in rat nervous tissue; in cerebellum and forebrain, additional 270-kD proteins were detected. In rat heart and skeletal muscle, both long and short C-terminal forms ... More on the omim web site
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 182790 was added.