Spectrin alpha chain, non-erythrocytic 1 (SPTAN1)
The protein contains 2472 amino acids for an estimated molecular weight of 284539 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.
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.
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Biological Process
Actin filament capping
Apoptotic process
Axon guidance
Cellular component disassembly involved in execution phase of apoptosis
Endoplasmic reticulum to Golgi vesicle-mediated transport
MAPK cascade
Neutrophil degranulation
The reference OMIM entry for this protein is 182810
Spectrin, alpha, nonerythrocytic 1; sptan1
Spectrin, nonerythroid, alpha subunit; neas
Spectrin, alpha-ii
Fodrin, alpha
DESCRIPTION
The spectrins, including nonerythrocytic alpha-spectrin-1 (SPTAN1), are a family of widely-distributed filamentous cytoskeletal proteins with have a highly conserved 106-amino acid repeat structure. Spectrins are heterodimers of a constant alpha-chain and variable, tissue-specific beta-chains. Functions of these proteins include regulation of receptor binding and actin crosslinking (Leto et al., 1988).CLONING
McMahon et al. (1987) cloned SPTAN1, which they termed alpha-fodrin, from a human lung fibroblast cDNA library. From this, they compared the structure of alpha-spectrin (SPTA1; 182860) and alpha-fodrin with deductions as to their evolution. The alpha-fodrin protein contains a 106-residue repeating structure, which is homologous with alpha-spectrin repeats 7 to 15. A 9-kb transcript was identified. A comparison of nucleic acid and amino acid homologies between alpha-spectrin and alpha-fodrin of several vertebrate species indicated that human nonerythroid alpha-fodrin and the common alpha-subunit of erythroid and nonerythroid cells of nonmammalian vertebrates are closely related (90 to 96% amino acid homology), whereas alpha-fodrin is only distantly related to the erythroid-specific alpha-spectrin subunit of mammals (55 to 59% amino acid homology). These data suggested that mammalian erythroid alpha-spectrin evolved by duplication and rapid divergence from an ancestral alpha-fodrin-like gene. Leto et al. (1988) used a probe for nonerythroid alpha-spectrin derived from a rat brain cDNA library to isolate the corresponding gene in man. They found close similarity of nonerythroid alpha-spectrin sequences in diverse species. Cianci et al. (1999) cloned a full-length SPTAN1 cDNA from a human fetal brain library. The deduced 2,477-residue protein has a predicted molecular mass of 285 kD. The protein contains 21 spectrin repeat units, a central SH3 domain, and a C-terminal EF-hand domain. They noted that the fundamental structural feature of the conserved spectrin repeat unit is a triple alpha-helical motif. In addition to 11 amino acid substitutions that differed from the transcript in human lung fibroblasts and likely represent polymorphisms, the human fetal brain SPTAN1 also had a 5-residue (15-bp) insertion in repeat unit 15 that arose from alternative splicing. Examination of several different mouse tissues demonstrated that the 5-residue insertion was found only in brain, heart, skeletal muscle, and embryonic tissues, while other isoforms were more widely distributed. Combined with other insertions, Cianci et al. (1999) predicted that at least 4, and as many as 8, different splice forms of the mature protein may be generated. Zhang et al. (2010) identified 2 novel alternatively spliced Sptan1 transcripts expressed only in the developing rat heart muscle. The transcripts contained a 21-residue insert in repeat 21 near the C terminus that was designated alpha-II-cardio+. The unique sequence occurs within the high affinity nucleation site for binding of alpha-II-spectrin to beta-spectrin, causing decreased binding, as shown by functional expression studies. Zhang et al. (2010) noted that 10 Sptan1 transcripts have now been identified in rat heart tissue.GENE STRUCTURE
Saitsu et al. (2010) stated that the SPTAN1 gene contains 57 exons.MAPPING
By somatic cell hybrid studies and in situ hybridization, Barton et al. (1987) and Leto et al. (1988) mapped the SPTAN1 gene to chromosome 9 ... 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 25, 2017: Additional information
No protein expression data in P. Mayeux work for SPTAN1
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 182810 was added.