Heat shock protein beta-1 (HSPB1)
The protein contains 205 amino acids for an estimated molecular weight of 22783 Da.
Small heat shock protein which functions as a molecular chaperone probably maintaining denatured proteins in a folding-competent state (PubMed:10383393, PubMed:20178975). Plays a role in stress resistance and actin organization (PubMed:19166925). Through its molecular chaperone activity may regulate numerous biological processes including the phosphorylation and the axonal transport of neurofilament proteins (PubMed:23728742). (updated: Dec. 20, 2017)
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.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- 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.
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Biological Process
Anterograde axonal protein transport
Cellular response to vascular endothelial growth factor stimulus
Chaperone-mediated protein folding
Gene expression
Intracellular signal transduction
Movement of cell or subcellular component
Negative regulation of apoptotic process
Negative regulation of oxidative stress-induced intrinsic apoptotic signaling pathway
Negative regulation of protein kinase activity
Platelet aggregation
Positive regulation of angiogenesis
Positive regulation of blood vessel endothelial cell migration
Positive regulation of endothelial cell chemotaxis
Positive regulation of endothelial cell chemotaxis by VEGF-activated vascular endothelial growth factor receptor signaling pathway
Positive regulation of interleukin-1 beta production
Positive regulation of tumor necrosis factor biosynthetic process
Positive regulation of tumor necrosis factor production
Regulation of autophagy
Regulation of I-kappaB kinase/NF-kappaB signaling
Regulation of mRNA stability
Regulation of protein phosphorylation
Regulation of translational initiation
Response to unfolded protein
Response to virus
Retina homeostasis
Vascular endothelial growth factor receptor signaling pathway
Viral process
Cellular Component
Axon cytoplasm
Cytoplasm
Cytoskeleton
Cytosol
Extracellular exosome
Extracellular matrix
Extracellular space
Focal adhesion
Nucleus
Plasma membrane
Proteasome complex
Spindle
Z disc
Molecular Function
Identical protein binding
Poly(A) RNA binding
Protein folding chaperone
Protein homodimerization activity
Protein kinase binding
Protein kinase C binding
Protein kinase C inhibitor activity
RNA binding
RNA polymerase II-specific DNA-binding transcription factor binding
Ubiquitin binding
The reference OMIM entry for this protein is 602195
Heat-shock 27-kd protein 1; hspb1
Heat-shock protein 27; hsp27
CLONING
The heat-shock proteins (HSPs) belong to a larger group of polypeptides, the stress proteins, that are induced in various combinations in response to environmental challenges and developmental transitions. Synthesis of the small (27-kD) HSP has been shown to be correlated with the acquisition of thermotolerance. Hickey et al. (1986) cloned a HeLa cell cDNA encoding HSP27. By screening a human genomic library with this HSP27 cDNA, Hickey et al. (1986) isolated the HSP27 genomic sequence. The deduced 199-amino acid HSP27 protein shows sequence similarity to mammalian alpha-crystallins (e.g., 123580). Approximately 20% of its residues are susceptible to phosphorylation. The HSP27 gene produced a 2.2-kb transcript in an in vitro transcription assay. Carper et al. (1990) cloned an HSP27 cDNA derived from heat-shocked human A549 lung carcinoma cells. The cDNA encodes a deduced 205-amino acid protein whose first 193 amino acids are identical to those of the predicted HSP27 protein reported by Hickey et al. (1986). Carper et al. (1990) suggested that the C-terminal differences of these deduced HSP27 proteins may be a result of a DNA sequencing artifact. - PSEUDOGENES Hickey et al. (1986) identified a processed HSP27 pseudogene.GENE STRUCTURE
Hickey et al. (1986) determined that the HSP27 gene has 3 exons.MAPPING
Hunt et al. (1997) mapped the mouse Hsp25 gene to chromosome 5 in a region homologous to 7q in the human. They also mapped the mouse Hsp105 gene to chromosome 5 but suggested that the human homolog is probably on 13q, not chromosome 7. Stock et al. (2003) used FISH to map the HSP27 gene to 7q11.23. This band also contains the site of the deletion associated with Williams syndrome (194050). Stock et al. (2003) used 2-color FISH on previously G-banded and photographed metaphase chromosomes from Williams syndrome cell lines and peripheral blood. In 6 Williams syndrome patients with longer deletions that extended telomeric to the classic Williams syndrome deletion region, they found that HSP27 was telomeric to several markers and was deleted in 3. They discussed the possible role of HSP27 in the cognitive features of Williams syndrome.GENE FUNCTION
New et al. (1998) demonstrated that MAPKAPK5 (606723) is a major stress-activated kinase that can phosphorylate HSP27 in vitro. Using a cellular model of Huntington disease (143100), Wyttenbach et al. (2002) identified HSP27 as a suppressor of polyglutamine (polyQ)-mediated cell death. In contrast to HSP40 (see 604572) and HSP70 (see 140550) chaperones, HSP27 suppressed polyQ death without suppressing polyQ aggregation. While polyQ-induced cell death was reduced by inhibiting cytochrome c release from mitochondria, protection by HSP27 was regulated by its phosphorylation status and was independent of its ability to bind to cytochrome c. However, mutant huntingtin (HTT; 613004) caused increased levels of reactive oxygen species (ROS) in neuronal and nonneuronal cells. ROS contributed to cell death because both N-acetyl-L-cysteine and glutathione in its reduced form suppressed polyQ-mediated cell death. HSP27 decreased ROS in cells expressing mutant huntingtin, suggesting that this chaperone may protect cells against oxidative stress. The authors proposed that a polyQ mutation may induce ROS that directly contribute to cell death, and that HSP27 may be an antagonist of this process. The alpha-crystallin subunits alpha-A (123580) and alpha-B (12 ... More on the omim web site
Feb. 10, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
Nov. 23, 2017: Protein entry updated
Automatic update: Uniprot description updated
June 20, 2017: Protein entry updated
Automatic update: comparative model was added.
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 602195 was added.
Jan. 24, 2016: Protein entry updated
Automatic update: model status changed