title: The protease degrading sperm histones post-fertilization in sea urchin eggs is a nuclear cathepsin L that is further required for embryo development.
abstract: Proteolysis of sperm histones in the sea urchin male pronucleus is the consequence of the activation at fertilization of a maternal cysteine protease. We previously showed that this protein is required for male chromatin remodelling and for cell-cycle progression in the newly formed embryos. This enzyme is present in the nucleus of unfertilized eggs and is rapidly recruited to the male pronucleus after insemination. Interestingly, this cysteine-protease remains co-localized with chromatin during S phase of the first cell cycle, migrates to the mitotic spindle in M-phase and is re-located to the nuclei of daughter cells after cytokinesis. Here we identified the protease encoding cDNA and found a high sequence identity to cathepsin proteases of various organisms. A phylogenetical analysis clearly demonstrates that this sperm histone protease (SpHp) belongs to the cathepsin L sub-type. After an initial phase of ubiquitous expression throughout cleavage stages, SpHp gene transcripts become restricted to endomesodermic territories during the blastula stage. The transcripts are localized in the invaginating endoderm during gastrulation and a gut specific pattern continues through the prism and early pluteus stages. In addition, a concomitant expression of SpHp transcripts is detected in cells of the skeletogenic lineage and in accordance a pharmacological disruption of SpHp activity prevents growth of skeletal rods. These results further document the role of this nuclear cathepsin L during development.
authors.affiliation: Department of Biochemistry and Molecular Biology, Universidad de Concepcion, Concepcion, Chile.
authors.forename: Violeta
authors.initials: V
authors.lastname: Morin
authors.forename: Andrea
authors.initials: A
authors.lastname: Sanchez-Rubio
authors.forename: Antoine
authors.initials: A
authors.lastname: Aze
authors.forename: Claudio
authors.initials: C
authors.lastname: Iribarren
authors.forename: Claire
authors.initials: C
authors.lastname: Fayet
authors.forename: Yves
authors.initials: Y
authors.lastname: Desdevises
authors.forename: Jenaro
authors.initials: J
authors.lastname: Garcia-Huidobro
authors.forename: Maria
authors.initials: M
authors.lastname: Imschenetzky
authors.forename: Marcia
authors.initials: M
authors.lastname: Puchi
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Genevière
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D056668:Cathepsin L / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D010450:Endopeptidases / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D005306:Fertilization; D018507:Gene Expression Regulation, Developmental; D006657:Histones / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012617:Sea Urchins / Q000166:cytology / Q000196:embryology* / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment; D013094:Spermatozoa / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; D006657:Histones; D010450:Endopeptidases; D056668:Cathepsin L; C021361:histone proteases