Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2003-3-20
pubmed:abstractText
The activated form of Ran (Ran-GTP) stimulates spindle assembly in Xenopus laevis egg extracts, presumably by releasing spindle assembly factors, such as TPX2 (target protein for Xenopus kinesin-like protein 2) and NuMA (nuclear-mitotic apparatus protein) from the inhibitory binding of importin-alpha and -beta. We report here that Ran-GTP stimulates the interaction between TPX2 and the Xenopus Aurora A kinase, Eg2. This interaction causes TPX2 to stimulate both the phosphorylation and the kinase activity of Eg2 in a microtubule-dependent manner. We show that TPX2 and microtubules promote phosphorylation of Eg2 by preventing phosphatase I (PPI)-induced dephosphorylation. Activation of Eg2 by TPX2 and microtubules is inhibited by importin-alpha and -beta, although this inhibition is overcome by Ran-GTP both in the egg extracts and in vitro with purified proteins. As the phosphorylation of Eg2 stimulated by the Ran-GTP-TPX2 pathway is essential for spindle assembly, we hypothesize that the Ran-GTP gradient established by the condensed chromosomes is translated into the Aurora A kinase gradient on the microtubules to regulate spindle assembly and dynamics.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1465-7392
pubmed:author
pubmed:issnType
Print
pubmed:volume
5
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
242-8
pubmed:dateRevised
2011-7-11
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
A Ran signalling pathway mediated by the mitotic kinase Aurora A in spindle assembly.
pubmed:affiliation
Department of Embryology, Carnegie Institution of Washington/Howard Hughes Medical Institute, Baltimore, MD 21210, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't