Hsp27 StressXpress® Human ELISA

Features

• ELISA kit used to quantitate Hsp27 concentration in samples
• The total assay time is less than 4 hours

Research topic

Neural tissue markers, Others

Summary

Hsp27s belong to an abundant and ubiquitous family of small heat shock proteins (sHSP). It is an important HSP found in both normal human cells and cancer cells. The basic
structure of most sHsps is a homologous and highly conserved amino acid sequence,
with an alpha-crystallin-domain at the C-terminus and the WD/EPF domain at the less
conserved N-terminus. This N-terminus is essential for the development of high molecular
oligomers (1, 2). Hsp27-oligomers consist of stable dimers formed by as many as 8-40
Hsp27 protein monomers (3). The oligomerization status is connected with the chaperone
activity: aggregates of large oligomers have high chaperone activity, whereas dimers have no
chaperone activity (4).
HSP27 is localized to the cytoplasm of unstressed cells but can redistribute to the nucleus
in response to stress, where it may function to stabilize DNA and/or the nuclear membrane.
Other functions include chaperone activity (as mentioned above), thermotolerance in
vivo, inhibition of apoptosis, and signal transduction. Specifically, in vitro, it acts as an
ATP-independent chaperone by inhibiting protein aggregation and by stabilizing partially
denatured proteins, which ensures refolding of the HSP70 complex. Hsp27 is also involved
in the apoptotic signaling pathway because it interferes with the activation of cytochrome
c/Apaf-1/dATP complex, thereby inhibiting the activation of procaspase-9. It is also
hypothesized that hsp27 may serve some role in cross-bridge formation between actin
and myosin (5). And finally, Hsp27 is also thought to be involved in the process of cell
differentiation. The up-regulation of Hsp27 correlates with the rate of phosphorylation
and with an increase of large oligomers. It is possible that Hsp27 may play a crucial role in
termination of growth (6