|Protein Name||Heat shock protein beta-1|
|Milk Fraction||MFGM, Exosome|
|Ref Sequence ID||XP_005225172.1|
|Protein Existence Status||Reviewed: Experimental evidence at transcript level|
|Presence in other biological fluids/tissue/cells||Ubiquitous, high levels in heart, striated and smooth muscles|
|Protein Function||also known as sHSP 27conserved across species and are important in stress tolerance; exhibit chaperone-like activity in preventing aggregation of target proteins; may exhibit immunomodulatory and anti-inflammatory functions; predominantly heat-inducible; involved in diverse cellular functions such as stress tolerance, protein folding, protein degradation, maintaining cytoskeletal integrity, cell death, differentiation, cell cycle and signal transduction and development; exhibit cardio and neuroprotection, potent anti-apoptotic activity, pro-angiogenic property and anti-inflammatory property involving interactions with several clients; bovine αBcrystallin prevent aggregation of citrate synthase and α-glucosidase|
|Biochemical Properties||bind Cu2+, and suppress generation of reactive oxygen species (ROS) ; Temperature-dependent conformational change in α-crystallin leading to the increased exposure of hydrophobic surfaces paralleled the increase in chaperone-like activity; undergoes thermally induced self-association, leading to increased oligomeric size, which correlated with increase in its chaperone-like activity; increase the refolding yields of citrate synthase and α-glucosidase upon refolding from their urea-denatured state|
|Significance in milk||heat stress proteins in mamary gland|
|PTMs||phosphorylated, especially under stress conditions - phosphorylation of serines(S), S15, S78, and S82 in human Hsp27;|
| Site(s) of PTM(s) |
|Predicted Disorder Regions|
|TM Helix Prediction||No TM helices|
|Significance of PTMs||sensitive to heat stress and mainly responsible for mammary cell protection from heat stress|
|Bibliography||1. Chowdary, T. K. et al. (2004) ‘Mammalian Hsp22 is a heat-inducible small heat-shock protein with chaperone-like activity.’, The Biochemical journal, 381(Pt 2), pp. 379–87. doi: 10.1042/BJ20031958. |
2. Fukuda, K. et al. (2011) ‘Biochemical, Proteomic, Structural, and Thermodynamic Characterizations of Integrin-linked Kinase (ILK)’, Journal of Biological Chemistry, 286(24), pp. 21886–21895. doi: 10.1074/jbc.M111.240093.
3. Jakob, U. et al. (1993) ‘Small heat shock proteins are molecular chaperones.’, The Journal of biological chemistry, 268(3), pp. 1517–20. Available at: http://www.ncbi.nlm.nih.gov/pubmed/8093612 (Accessed: 4 October 2019).
4. Raman, B. and Rao, C. M. (1994) ‘Chaperone-like activity and quaternary structure of alpha-crystallin.’, The Journal of biological chemistry, 269(44), pp. 27264–8. Available at: http://www.ncbi.nlm.nih.gov/pubmed/7961635 (Accessed: 4 October 2019).
5. Lelj-Garolla, B. and Mauk, A. G. (2006) ‘Self-association and Chaperone Activity of Hsp27 Are Thermally Activated’, Journal of Biological Chemistry, 281(12), pp. 8169–8174. doi: 10.1074/jbc.M512553200.
6. Landry, J. et al. (1992) ‘Human HSP27 is phosphorylated at serines 78 and 82 by heat shock and mitogen-activated kinases that recognize the same amino acid motif as S6 kinase II.’, The Journal of biological chemistry, 267(2), pp. 794–803. Available at: http://www.ncbi.nlm.nih.gov/pubmed/1730670 (Accessed: 4 October 2019).
7. Rogalla, T. et al. (1999) ‘Regulation of Hsp27 Oligomerization, Chaperone Function, and Protective Activity against Oxidative Stress/Tumor Necrosis Factor α by Phosphorylation’, Journal of Biological Chemistry, 274(27), pp. 18947–18956. doi: 10.1074/jbc.274.27.18947.