Human Phospho-HSP27 (S78/S82) Antibody

Heat shock proteins (HSPs) are a family of highly conserved stress response proteins. Heat shock proteins function primarily as molecular chaperones by facilitating the folding of other cellular proteins, preventing protein aggregation or targeting improperly folded proteins to specific degradative pathways. HSPs are typically expressed at low levels under normal physiological conditions but are dramatically up-regulated in response to cellular stress. Elevated levels of HSPs have been observed in association with ischemia/reperfusion, cancer, and chronic heart failure. HSP27 is a member of the small heat shock protein family, which also includes HSP25 and the alpha-crystallins. Ser78 and Ser82 of HSP27 are phosphorylated in vivo in response to growth factors or heat shock, and the extent of phosphorylation plays a role in determining specific functions. HSP27 forms a large oligomer and functions as an anti-apoptotic molecule, regulating apoptosis through direct interaction with key components of the apoptotic pathway. HSP27 binds and sequesters cytochrome c released from the mitochondria in response to an apoptotic stimulus. This prevents the proper assembly of the apoptosome and subsequently, the activation of procaspase-9 and procaspase-3.