L. Ding et Epm. Candido, HSP25, a small heat shock protein associated with dense bodies and M-linesof body wall muscle in Caenorhabditis elegans, J BIOL CHEM, 275(13), 2000, pp. 9510-9517
HSP25, a previously uncharacterized member of the alpha-crystallin family o
f small heat shock proteins in Caenorhabditis elegans, has been examined us
ing biochemical and immunological techniques. HSP25 is the second largest o
f 16 identifiable small heat shock proteins in the nematode and is expresse
d at all developmental stages under normal growth conditions. Recombinant H
SP25 produced in Escherichia coil exists predominantly as small oligomers (
dimers to tetramers) and possesses chaperone activity against citrate synth
ase in vitro. In C. elegans, HSP25 is localized to dense bodies and M-lines
in body wall muscle, to the lining of the pharynx, and to the junctions be
tween cells of the spermathecal wall. Affinity chromatography of nematode e
xtracts on a column of immobilized HSP25 resulted in specific binding of vi
nculin and alpha-actinin but not actin, as revealed by Western blotting. Th
ese results suggest a role for HSP25 in the organization or maintenance of
the myofilament lattice and adherens junctions in C. elegans.