Identification and characterization of a constitutive HSP75 in sea urchin embryos.
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 hsc in the sea urchin P. lividus. This hsc was present both during oogenesis and at all developmental stages. A two-dimensional electrophoresis has revealed four isolectric forms of this 75-kDa hsc. The amino acid sequence of the fragment used to prepare the anti-hsp70 antibodies revealed a 43% identity with the corresponding part of sea urchin sperm 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 not in the nuclei. In the embryos a higher hsp75 concentration was found in the portion facing the lumen of the cells which invaginate at gastrulation.
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Dipartimento di Biologia Cellulare e dello Sviluppo, Alberto Monroy Viale delle Scienze Università di Palermo, Italy. Gasc@mbox.unipa.it
Amore
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Giudice
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Cascino
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Ghersi
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D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D003593:Cytoplasm / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D004625:Embryo, Nonmammalian / Q000737:chemistry*; D047108:Embryonic Development; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis* / Q000737:chemistry; D007150:Immunohistochemistry; D007526:Isoelectric Point; D008297:Male; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009865:Oocytes / Q000737:chemistry; D009866:Oogenesis; D010053:Ovary / Q000166:cytology; D010957:Plasmids / Q000235:genetics; D011956:Receptors, Cell Surface / Q000737:chemistry / Q000378:metabolism; D011993:Recombinant Fusion Proteins; D012617:Sea Urchins; D017386:Sequence Homology, Amino Acid; D013094:Spermatozoa / Q000737:chemistry
D018840:HSP70 Heat-Shock Proteins; C491063:HSP75 protein, sea urchin; D011956:Receptors, Cell Surface; D011993:Recombinant Fusion Proteins; C035027:egg surface sperm receptor