Syntaxin-binding protein 2 (STXBP2)
The protein contains 593 amino acids for an estimated molecular weight of 66453 Da.
Involved in intracellular vesicle trafficking and vesicle fusion with membranes. Contributes to the granule exocytosis machinery through interaction with soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins that regulate membrane fusion. Regulates cytotoxic granule exocytosis in natural killer (NK) cells. (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.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- 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 Gene Ontology.
Biological Process
Cellular response to interferon-gamma
Intracellular protein transport
Leukocyte mediated cytotoxicity
Neurotransmitter secretion
Neutrophil degranulation
Platelet degranulation
Protein transport
Regulation of mast cell degranulation
Vesicle docking involved in exocytosis
Vesicle-mediated transport
The reference OMIM entry for this protein is 601717
Syntaxin-binding protein 2; stxbp2
Unc18, c. elegans, homolog of, 2
Unc18b
Munc18-2
DESCRIPTION
Several mammalian homologs of the C. elegans gene Unc18 have been identified, including STXBP2. These genes are conserved across species from yeast to man and are believed to take part in membrane-fusion processes. See STXBP1 (602926).CLONING
Ziegler et al. (1996) identified STXBP2, which they called UNC18B, as part of a random sequencing of genes from IL2-activated human natural-killer (NK) cells. Sequence analysis of a full-length cDNA revealed that it encodes a polypeptide of 593 amino acids, which is most closely related to mouse Unc18b (95% identical) and less closely related to Unc18a (64% identical) and Unc18c (48% identical). Ziegler et al. (1996) found by Northern blot analysis that UNC18B is expressed predominantly as a 2.4-kb message in placenta, lung, liver, kidney, and pancreas, as well as in peripheral blood lymphocytes.GENE STRUCTURE
Zur Stadt et al. (2009) noted that the STXBP2 gene contains 19 exons.MAPPING
Ziegler et al. (1996) mapped the STXBP2 gene to human chromosome 19p13.3-p13.2 and to the proximal arm of mouse chromosome 8.GENE FUNCTION
Zur Stadt et al. (2009) demonstrated colocalization of STXBP2 and STX11 (605014) in CD8+ T and NK cells by immunofluorescence analysis. Stimulation with IL2 (147680) further enhanced colocalization in CD8+ and NK cells. Coimmunoprecipitation analysis demonstrated shared binding sites between STXBP2 and STX11.MOLECULAR GENETICS
In 8 unrelated probands with familial hemophagocytic lymphohistiocytosis (FHL) mapping to chromosome 19p (FHL5; 613101), from 2 Saudi Arabian and 6 Turkish consanguineous families, zur Stadt et al. (2009) sequenced the candidate gene STXBP2 and identified homozygous mutations in STXBP2 in all 8 patients (see, e.g., 601717.0001-601717.0003). Sequence analysis in other patients from nonconsanguineous FHL families revealed homozygosity or compound heterozygosity for mutations in STXBP2 in 4 additional patients from Germany and the Czech Republic (see, e.g., 601717.0004-601717.0006), 2 of whom had been previously reported (Beutel et al., 2009; Sparber-Sauer et al., 2009). Corresponding heterozygous mutations were found in all available unaffected parents, and none of the mutations were detected in 210 chromosomes from ethnically matched controls. Zur Stadt et al. (2009) identified STX11, a mutation in which causes FHL4 (603552), as an interaction partner of STXBP2, and demonstrated that this interaction is eliminated by the missense mutations identified in the FHL5 patients, leading to decreased stability of both proteins. Activity of NK and cytotoxic T cells was markedly reduced or absent in FHL5 patients. In affected members of 6 consanguineous families with FHL mapping to chromosome 19p13.3-p13.2, Cote et al. (2009) sequenced the STXBP2 gene and identified homozygosity for the P477L mutation (601717.0001) in 3 Saudi Arabian families and for the IVS14 splice site mutation (601717.0003) in 3 families of Turkish, Palestinian Arab, and Iranian origin, respectively. Cetica et al. (2010) analyzed the STXBP2 gene in 28 FHL families in which mutations in known FHL genes had been excluded by sequence analysis, and identified homozygosity for 4 different missense mutations in the STXBP2 gene in 4 (14%) of the 28 families, originating from Italy, England, Kuwait, and Pakistan, respectively (see, e.g., 601717.0001 and 601717.0007). ... 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 STXBP2
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 601717 was added.
Jan. 28, 2016: Protein entry updated
Automatic update: model status changed
Jan. 25, 2016: Protein entry updated
Automatic update: model status changed