Phospho-HSPB1 (Ser15) Antibody
Description
Biological Role of HSPB1 Phosphorylation at Ser15
Phosphorylation at Ser15 modulates HSPB1’s oligomerization, chaperone activity, and interactions with cytoskeletal components. Key findings include:
Mechanotransduction and Actin Remodeling
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HSPB1 phosphorylation at Ser15 is induced by p38-MAPK signaling in response to mechanical stress (e.g., cyclic stretch) .
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Phosphorylated HSPB1 (pHSPB1) associates with F-actin and promotes cytoskeletal reorganization, cell spreading, and motility .
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CRISPR-edited HspB1-null cells show impaired actin remodeling, rescued only by phosphomimetic (S15E) mutants .
Chaperone Activity and Protein Interactions
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Phosphorylation reduces HSPB1 oligomer size, enhancing its ability to bind substrates like filamin C (FLNC) .
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HSPB1 interacts with FLNC’s Ig domains (residues 18–21), forming aggregates modulated by Ser15 phosphorylation .
Disease Relevance
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Cancer: Phospho-HSPB1 (Ser15) inhibits ferroptosis by reducing lipid ROS and iron uptake, promoting tumor survival .
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Cardiomyopathy: Upregulated phospho-HSPB1 colocalizes with FLNC in stressed cardiac tissue, suggesting a role in mechanical stress adaptation .
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Neurodegeneration: HSPB1 phosphorylation regulates axonal transport and neurofilament stability, linked to Charcot-Marie-Tooth disease .
Key Research Findings
The table below summarizes critical studies utilizing Phospho-HSPB1 (Ser15) antibodies:
Technical Considerations
Product Specs
Target Background
- Data suggest that both the small heat shock protein HspB1/Hsp27 and the constitutive chaperone Hsc70/HspA8 interact with tau to prevent tau-fibril/amyloid formation. HspB1 delays tau-fibril formation by weakly interacting with early species in the aggregation process. (HspB1 = heat shock protein family B small member 1; Hsc70 = heat shock protein family A Hsp70) PMID: 29298892
- HSP27 is a partner of JAK2-STAT5 and a potential therapeutic target in myelofibrosis. PMID: 29650953
- Results show that HSP27 expression is significantly increased in metastatic prostate cancer and represents a strong marker predicting survival, along with ALDH6A1 and prohibitin. PMID: 30396985
- High HSP27 expression is associated with breast cancer. PMID: 30106436
- Our data suggest that overexpression of peroxiredoxin-2, annexin A2, and heat shock protein beta-1 was correlated with tumor invasion, metastasis, and poor prognosis, and therefore, these proteins may serve as potential diagnostic and therapeutic biomarkers. PMID: 29332450
- ETAS down-regulated HSP27 and pHSP27 (serine 78) in KLM1-R cells, but, HSP70 and GRP78 levels were not altered. This study suggests the potential therapeutic benefit of ETAS in enhancing anticancer effects by its combination with gemcitabine for patients with pancreatic cancer. PMID: 29936456
- Silencing of HSP27 increases curcumin resistance by reducing apoptosis and reactive oxidative stress production in colon cancer. PMID: 30056019
- The expression of type I and III collagen in the TGF-beta1-induced transition of A549 cells to myofibroblasts was significantly downregulated by transfection of A549 cells with HSP27 plasmid D-interfering sequence and optimal ratio of Lipofectamine(R) 2000 and HSP27 plasmid. PMID: 29568951
- It was suggested that the HSP27 expression in EUS-FNA samples was useful for predicting GEM sensitivity. PMID: 29695571
- High hsp27 expression is associated with leukemia. PMID: 29328466
- p-Hsp27 is a novel biomarker of glioma and might have important clinical value for further classification of patients with wild-type IDH1 and normal ATRX expression and for evaluating prognosis. PMID: 29550762
- Dimer-monomer equilibrium of human HSP27 is influenced by the in-cell macromolecular crowding environment and is controlled by fatty acids and heat. PMID: 29635040
- HSP27 expression promotes vascular smooth muscle cell viability, suppresses cell apoptosis, and confers protection against oxidative stress in Thoracic aortic dissection. PMID: 29209372
- Hsp27 and P38MAPK could be used as prognostic factors in Esophageal squamous cell carcinoma. PMID: 29099815
- Addition of apatorsen to chemotherapy does not improve outcomes in unselected patients with metastatic pancreatic cancer in the first-line setting, although a trend toward prolonged PFS and OS in patients with high baseline serum Hsp27 suggests this therapy may warrant further evaluation in this subgroup. PMID: 28935773
- High HSP27 expression is associated with non-small cell lung cancer metastasis. PMID: 28656293
- Knockdown of HSP27 blocked TGF-beta-induced cisplatin resistance. PMID: 28848138
- The expression of HSP27 was approximately 2-fold higher in apical periodontitis. Next, an increased expression of HSP27 was detected in epithelial cells. PMID: 28673495
- Findings indicate the heat-shock protein 27 (Hsp27) pathway as a therapeutic target for the management of conditions featuring dysregulated interleukin 1 beta (IL-1beta) production. PMID: 27976724
- Increased protein level of HSP27 through SUMO2/3-mediated SUMOylation plays crucial roles in the progression of primary hepatocellular carcinoma. PMID: 28665748
- When the correlations of the markers with the response to neoadjuvant chemotherapy were examined, only high pre-chemotherapy levels of cytoplasmic HSPB1/p correlated with a poor clinical and pathological response to neoadjuvant cisplatin chemotherapy (p = 0.056) suggesting that this marker could be useful, warranting further investigation in a larger number of cases. PMID: 28608263
- Exposure to cetuximab and various concentrations of AG490, an inhibitor of JAK2, STAT3 and HSP27 protein levels, except in the KRAS G12V mutant line, SW620...cetuximab may promote SN38 sensitivity via suppression of HSP27, through blocking the JAK/STAT signaling pathway, and shows synergistic effects when combined with SN38 in wild-type RAS CRC cells. PMID: 28656305
- We concluded that HSP27-silenced placenta-derived multipotent cells differentiated into neurons possessing the characteristics of functional glutamatergic neurons. PMID: 27444754
- Data show that Hsp27 increases the degradation rate of ubiquitinated MST1 and therefore interrupts the Hippo pathway kinase cascade. Consequently, YAP and TAZ are less phosphorylated, free to translocate into the nucleus, promoting a malignant phenotype. These findings underscore the central importance of Hsp27 in regulating multiple signaling pathways that promote tumor aggressiveness. PMID: 27555231
- Upregulation of Hsp27 is a common phenomenon shared between pregnancies in patients with preterm prelabor rupture of membranes and spontaneous preterm labor with intact membranes. PMID: 28497897
- HSP27 is an independent predictor of prognosis in chronic HF. PMID: 28844461
- Hsp27 may up-regulate the expression of ABCA1 and promotes cholesterol efflux through activation of the PI3K/PKCzeta/Sp1 signal pathway in THP-1 macrophage-derived foam cells. PMID: 28610841
- This study reports solution-state nuclear magnetic resonance spectroscopy investigations of the conformation and dynamics of the disordered and flexible C-terminal region of human HSP27. These data indicate a potential role for cis-trans proline isomerization in regulating the oligomerization. PMID: 28547731
- Overexpression of both HSPB5 and Hsp27 significantly reduced the intracellular aggregation of alpha-synuclein. PMID: 28337642
- HspB1 structural organization displays dynamic and complex rearrangements in response to changes in the cellular environment or when the cell physiology is modified. [review] PMID: 28144778
- Glutathione-S-transferase - HspB1 fusion protein prevents more aggregation of malate dehydrogenase compared to glutathione-S-transferase -HspB5 fusion protein and wild type HspB1. PMID: 28130664
- The data suggest that oncogene-addicted cells require the small heat-shock protein of 27 kDa (HSP27) for survival and that HSP27 might interfere with the effectiveness of targeted agents. PMID: 28182330
- Data indicate six cytostatic drugs which inhibit heat shock 27 kDa protein (HSP27) and tackle drug resistance by computational drug repositioning approach. PMID: 27626687
- Different from C-M-T phenotype in hereditary neuropathies caused by mutations in the HSPB1 gene. PMID: 27816334
- Found knock down of HSPB1 further increased the proportion of apoptotic cells in hyperthermic treated melanoma cells when compared with either single agent alone, and both agents leaded to cell cycle arrest at G0/G1 or G2/M phases. PMID: 27626679
- Data suggest that altered dimerization of HSP27 represents a good strategy for anticancer therapy in HSP27-overexpressing cancer cells. PMID: 27449291
- Apatorsen (2'-methoxyethyl-modified antisense oligonucleotide that inhibits Hsp27 expression) was tolerated at the highest dose evaluated (1000 mg). Single-agent activity was suggested by changes in tumor markers, circulating tumor cells, and stable measurable disease. PMID: 27022067
- These results show the central role of Hsp27 in RACK1 pseudosubstrate or LPS-induced cell activation of primary leukocytes. PMID: 27178349
- High p-Hsp27 expression is associated with cisplatin resistance in lung cancer. PMID: 26872057
- Low p-Hsp27 expression is associated with pancreatic cancer. PMID: 26895107
- The up-regulation of Hsp27 by E2 is mediated by ERalpha/Sp1. PMID: 27179757
- Study report a novel interaction between mutant HSPB1-P182L and the RNA binding protein PCBP1, leading to a reduction in its translational repression activity. Identifying PCBP1 mRNA targets revealed a marked prevalence for an RNA recognition motif, preferably seen in their 5' and 3'UTRs. Findings further support a role for mutant HSPB1 in neurodegenerative diseases. PMID: 28077174
- Hsp 70 and Hsp 27 were expressed in middle ear effusions. PMID: 28964286
- High Hsp27 expression is associated with Thyroid Tumors. PMID: 26970173
- Bradykinin stimulates myofibroblast migration through protein kinase D-mediated activation of COX-2 and Hsp27. PMID: 28032559
- Data suggest that HSPB6 forms hetero-oligomers with HSPB1 under the following rules: (1) highly conserved motif RLFDQXFG is necessary for subunit exchange among oligomers, (2) a site about 20 residues downstream of this motif determines size of resultant hetero-oligomers, and (3) a region in the N-terminal domain that is unique to HSPB6 dictates preferential formation of heterodimers. (HSP = heat shock protein) PMID: 28487364
- TNF-alpha stimulates colonic myofibroblast migration through P38 MAPK-mediated activation of COX-2 and Hsp27. PMID: 27451881
- The potency of the sHsps to suppress aggregation of model substrates is correlated with their ability to form stable substrate complexes; especially HspB1 and HspB5, but also B3, bind tightly to a variety of proteins. PMID: 27909051
- This work examines the molecular mechanism by which two canonical sHsps, alphaB-crystallin (alphaB-c) and Hsp27, interact with aggregation-prone alpha-syn to prevent its aggregation in vitro. Both sHsps are very effective inhibitors of alpha-syn aggregation. PMID: 27587396
- This study highlights a novel relation between serum pHSP27 and BMD in Indian women; however, these findings need to be confirmed in larger studies. PMID: 27241641
Q&A
What is Phospho-HSPB1 (Ser15) Antibody and what epitope does it recognize?
Phospho-HSPB1 (Ser15) antibody is a rabbit polyclonal antibody that specifically recognizes Heat Shock Protein Beta-1 (HSPB1/HSP27) only when phosphorylated at serine 15. The antibody is typically generated using a synthetic phosphopeptide derived from human HSP27 surrounding the Ser15 phosphorylation site, with immunogens commonly corresponding to amino acids 5-54 or 1-80 of the protein sequence . This antibody is crucial for studying post-translational modifications that regulate HSPB1 function in various cellular processes.
What applications are supported by Phospho-HSPB1 (Ser15) Antibody?
Phospho-HSPB1 (Ser15) antibody has been validated for multiple research applications:
| Application | Recommended Dilution | Notes |
|---|---|---|
| Western Blot (WB) | 1:500-1:2000 | Detects endogenous levels of phosphorylated HSPB1 |
| Immunohistochemistry (IHC) | 1:100-1:300 | Works with paraffin-embedded tissues |
| Immunofluorescence (IF) | 1:50-200 | Useful for subcellular localization studies |
| ELISA | 1:20000 | High sensitivity for quantitative analysis |
For optimal results, the exact dilution should be determined experimentally for each specific application and sample type .
What species reactivity has been confirmed for Phospho-HSPB1 (Ser15) Antibody?
The antibody demonstrates confirmed reactivity with human and monkey samples across multiple sources . Some commercial antibodies also claim reactivity with mouse and rat samples . Predicted cross-reactivity (though requiring validation) has been suggested for pig, zebrafish, bovine, horse, rabbit, dog, and chicken models based on sequence homology .
How should I prepare samples for optimal detection of phosphorylated HSPB1?
To effectively detect phosphorylated HSPB1:
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Include phosphatase inhibitors in lysis buffers to prevent dephosphorylation during sample preparation
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For Western blotting, consider using fresh samples as phosphorylation states can be labile
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When working with tissue samples, rapid fixation is critical to preserve phosphorylation status
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For cellular stimulation experiments that induce HSPB1 phosphorylation, treatments like UV exposure have been demonstrated to effectively increase Ser15 phosphorylation
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For verification of specificity, include both positive controls (stimulated cells) and negative controls (phosphatase-treated samples)
What are the recommended storage conditions for maintaining antibody efficacy?
For optimal long-term stability:
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Store the antibody at -20°C for up to one year from the date of receipt
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Avoid repeated freeze/thaw cycles that can diminish activity
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The antibody is typically supplied in PBS containing 50% glycerol, 0.5% BSA, and 0.02% sodium azide as stabilizers
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For working aliquots, prepare small volumes to minimize freeze/thaw cycles
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Return antibody to appropriate storage temperature promptly after use
What signaling pathways regulate HSPB1 Ser15 phosphorylation?
HSPB1 Ser15 phosphorylation is primarily regulated through the p38 mitogen-activated protein kinase (MAPK) signaling cascade. Key elements of this pathway include:
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Upstream activators: Cellular stress factors, including mechanical stimulation like uniaxial cyclic stretch
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MAPK cascade: Activation of p38 MAPK
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Effector kinases: MAPKAPK2 (MK2) and MAPKAPK3 directly phosphorylate HSPB1 at Ser15
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Additional regulation: MAPKAPK5 can also induce phosphorylation in response to PKA stimulation
Research has demonstrated that uniaxial cyclic stretch stimulation increases phospho-HSPB1 signal by approximately 1.9-fold compared to unstimulated fibroblasts .
How does phosphorylation affect the oligomeric state and function of HSPB1?
Phosphorylation of HSPB1 has significant impacts on its quaternary structure and function:
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Phosphorylation (particularly at Ser15 and Ser86 in murine HSPB1) dissociates HSPB1 from large small heat-shock protein (sHsps) oligomers
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This structural change alters its chaperone activity and ability to protect against oxidative stress
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Phosphorylation by MAPKAPK5 in response to PKA stimulation specifically induces F-actin rearrangement
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These modifications appear critical for mechanotransduction, as only phosphorylatable HSPB1 displayed mechanoaccumulation to tensed actin stress fibers
How can phospho-mutants be used to study HSPB1 function?
Phospho-mutants provide powerful tools for investigating the specific roles of HSPB1 phosphorylation:
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Non-phosphorylatable mutants: S15,86A HSPB1 (serine replaced with alanine) prevents phosphorylation at these sites
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Phosphomimetic mutants: S15,86E HSPB1 (serine replaced with glutamate) can simulate constitutive phosphorylation
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Rescue experiments: Using these constructs in HSPB1-null cells enables assessment of phosphorylation-dependent functions
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Localization studies: Research demonstrates that phosphorylation status determines subcellular distribution patterns
In geometric constraint experiments, only wild-type and phosphomimetic HSPB1 (S15,86E) accumulated at high-tension edges and corners near focal adhesions, while non-phosphorylatable HSPB1 (S15,86A) showed diffuse cytoplasmic distribution, indicating that phosphorylation directs HSPB1 to sites of cytoskeletal tension .
What experimental approaches can validate phospho-specific antibody specificity?
To ensure antibody specificity for phosphorylated Ser15 HSPB1:
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Peptide competition assays: Pre-incubation with the phospho-peptide immunogen should block specific antibody binding
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Phosphatase treatment: Treating samples with phosphatases should eliminate signal
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Comparison with phospho-mutants: S15A mutants should show no reactivity
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Stimulus-response verification: Signal should increase following treatments known to enhance Ser15 phosphorylation (e.g., UV treatment of HeLa cells)
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Dual detection approach: Using both phospho-specific and total HSPB1 antibodies to confirm the presence of the protein
How does HSPB1 phosphorylation regulate cytoskeletal dynamics and cell behavior?
Phosphorylation of HSPB1 at Ser15 plays critical roles in cytoskeletal regulation:
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Actin remodeling: Phosphorylated HSPB1 modulates actin stress fiber organization in response to mechanical stimuli
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Cell spreading: HSPB1-null cells show altered spreading patterns that can be rescued by wild-type or phosphomimetic HSPB1, but not by non-phosphorylatable variants
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Cell motility: Phosphorylation status affects migration capabilities, with phosphorylation-competent HSPB1 being required
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Mechanotransduction: Phosphorylated HSPB1 serves as a critical link between mechanical forces and cellular responses
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Subcellular localization: Phosphorylation directs HSPB1 to specific tension-bearing structures within the cell
What is the tissue distribution profile of HSPB1?
HSPB1 (Heat Shock Protein Beta-1) shows widespread but variable expression across tissues:
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Ubiquitous expression: Detected in all tested tissues including skeletal muscle, heart, aorta, intestines, stomach, esophagus, bladder, adrenal gland, thyroid, pancreas, testis, adipose tissue, kidney, liver, spleen, cerebral cortex
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Highest expression: Found in the heart and tissues composed of striated and smooth muscle
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Fluid presence: Detected in both blood serum and cerebrospinal fluid
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Subcellular localization: Primarily cytoplasmic in interphase cells, but can colocalize with mitotic spindles during cell division
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Stress response: Translocates to the nucleus during heat shock, specifically to sub-nuclear structures known as SC35 speckles or nuclear splicing speckles
What technical considerations are important when comparing phospho-HSPB1 levels between different experimental conditions?
When conducting comparative studies of phospho-HSPB1 levels:
