Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-7-12
pubmed:abstractText
The Lsc RhoGEF (also known as p115-RhoGEF) is a GTP exchange factor (GEF), an activator of GTPases of the Rho family. Lsc has a RhoGEF domain specific for Rho GTPase and a regulator of G protein signaling (RGS) domain specific for Galpha(12/13) subunits. One G protein receptor that can couple to Galpha(12/13) subunits is the receptor for thromboxane A(2 )(TXA(2)), thromboxane-prostanoid (called TP), which is highly expressed in immature thymocytes. TXA(2) has been implicated in thymocyte apoptosis. We found that Lsc(-/-) mice on a BALB/c background show thymic hyperplasia due to increased numbers of thymocytes and that these numbers further increase with the age of the mice. To investigate a role for Lsc in TXA(2) signaling, we analyzed activation of primary thymocytes by TXA(2) in vitro. TXA(2)-induced apoptosis of double-positive thymocytes and Rho activation required Lsc, and TXA(2) stimulation of actin polymerization and cofilin phosphorylation required both Lsc and Rho kinase (ROCK). Additionally, in the absence of Lsc, phosphorylation of the survival kinase Akt in response to TXA(2) was greatly enhanced. Together, these data demonstrate that Lsc is essential for mediating TXA(2 )signaling involved in apoptosis and actin organization and suggest that TXA(2) regulates thymic cellularity via Lsc.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0014-2980
pubmed:author
pubmed:issnType
Print
pubmed:volume
35
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1977-86
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
The Lsc RhoGEF mediates signaling from thromboxane A2 to actin polymerization and apoptosis in thymocytes.
pubmed:affiliation
Department of Physiological Chemistry, University of Ulm, Ulm, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't