Linked Life Data

11984838

Source:http://linkedlifedata.com/resource/pubmed/id/11984838

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-5-23
pubmed:abstractText
We previously reported that sperm proteasome is responsible for degradation of the ubiquitinated vitelline-coat during fertilization in the ascidian Halocynthia roretzi. Here, we report the roles in fertilization and localization in the sperm cell surface of H. roretzi sperm proteasome. An anti-proteasome antibody, as well as the proteasome inhibitors MG115 and MG132, inhibited the fertilization, indicating that the sperm proteasome functions extracellularly in ascidian fertilization. In order to further assess this issue, the sperm surface proteasome activity was labeled with a cell-impermeable labeling reagent, NHS-LC-biotin, extracted with 0.1% CHAPS, and was subjected to a pull-down assay with avidin-agarose beads. It was found that a substantial amount of sperm proteasome is exposed to the cell surface. Partition analysis with Triton X-114 also revealed that a considerable amount of the sperm proteasome activity is partitioned into a lipid layer. Localization of the proteasome activity was investigated by fluorescence microscopy with succinyl-Leu-Leu-Val-Tyr-4-methylcoumaryl-7-amide as a substrate. The sperm proteasome activity was specifically detected in the sperm head region, and it was markedly activated upon sperm activation. The membrane-associated proteasome was purified from the membrane fraction of H. roretzi sperm by affinity chromatography using an anti-20S proteasome antibody-immobilized Sepharose column. SDS-PAGE of the purified preparation showed a similar pattern of subunit composition to that of the 26S proteasome of mammalian origin. Taken together, these results indicate that H. roretzi sperm has the membrane-associated proteasome on its head, which is activated upon sperm activation, and that sperm proteasome plays an essential role in H. roretzi fertilization.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1040-452X
pubmed:author
pubmed:copyrightInfo
Copyright 2002 Wiley-Liss, Inc.
pubmed:issnType
Print
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
271-6
pubmed:dateRevised
2004-11-17
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Localization and roles in fertilization of sperm proteasomes in the ascidian Halocynthia roretzi.
pubmed:affiliation
Department of Biochemistry, Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan. hswd@pharm.hokudai.ac.jp
pubmed:publicationType
Journal Article