G. Sconzo et al., IDENTIFICATION AND CHARACTERIZATION OF A CONSTITUTIVE HSP75 IN SEA-URCHIN EMBRYOS, Biochemical and biophysical research communications, 234(1), 1997, pp. 24-29
An antiserum against a hsp of the 70-kDa family was prepared, by means
of a fusion protein, which was able to detect a constitutive 75-kDa h
sc in the sea urchin P. lividus. This hsc was present both during ooge
nesis and at all developmental stages. A two-dimensional electrophores
is has revealed four isolectric forms of this 75-kDa hsc. The amino ac
id sequence of the fragment used to prepare the anti-hsp70 antibodies
revealed a 43% identity with the corresponding part of sea urchin sper
m receptor, and in mature eggs a brighter immunofluorescence was seen
all around the cell cortex where the receptor for sea urchin sperm is
localized. In oocytes the hsp75 was localized in the cytoplasms but no
t in the nuclei. In the embryos a higher hsp75 concentration was found
in the portion facing the lumen of the cells which invaginate at gast
rulation. (C) 1997 Academic Press.