Linked Life Data

19996184

Source:http://linkedlifedata.com/resource/pubmed/id/19996184

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2010-1-26
pubmed:abstractText
Completion of the first meiosis in oocytes is achieved by the extrusion of the first polar body (PBI), a particular example of cell division. In mitosis, the small GTPase RhoA, which is activated by epithelial cell transforming protein 2 (ECT2), orchestrates contractile ring constriction, thus enabling cytokinesis. However, the involvement of this pathway in mammalian oocytes has not been established. To characterize the role of ECT2 in PBI emission in mouse oocytes, the small interfering RNA approach was employed. We found that ECT2 depletion significantly reduces PBI emission, induces first metaphase arrest, and generates oocytes containing two properly formed spindles of the second metaphase. Moreover, we describe, for the first time, that before PBI emission, RhoA forms a ring that is preceded by a dome-like accumulation at the oocyte cortex, next to the spindle. This unique mode of RhoA translocation failed to occur in the absence of ECT2. We further found that the Rho-dependent kinase, a main RhoA effector, is essential for PBI emission. In addition, we demonstrate herein that ECT2 is subjected to phosphorylation/dephosphorylation throughout meiosis in oocytes and further reveal that PBI emission is temporally associated with ECT2 dephosphorylation. Our data provide the first demonstration that an active cyclin-dependent kinase 1, the catalytic subunit of the maturation-promoting factor, phosphorylates ECT2 during the first meiotic metaphase and that cyclin-dependent kinase 1 inactivation at anaphase allows ECT2 dephosphorylation. In conclusion, our study demonstrates the indispensable role of the maturation-promoting factor/ECT2/RhoA pathway in PBI extrusion in mouse oocytes.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1945-7170
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
151
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
755-65
pubmed:meshHeading
pubmed:year
2010
pubmed:articleTitle
Epithelial cell transforming protein 2 (ECT2) depletion blocks polar body extrusion and generates mouse oocytes containing two metaphase II spindles.
pubmed:affiliation
Weizmann Institute of Science, Department of Biological Regulation, Herzel Street 1, Rehovot 76100, Israel.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't