Linked Life Data

17681754

Source:http://linkedlifedata.com/resource/pubmed/id/17681754

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
2007-8-13
pubmed:abstractText
Two mechanisms for store-operated Ca(2+) entry (SOCE) regulated by two independent Ca(2+) stores, the dense tubular system (DTS) and the acidic stores, have been described in platelets. We have previously suggested that coupling between the type II IP(3) receptor (IP(3)RII) and hTRPC1, involving reorganization of the actin microfilaments, play an important role in SOCE. However, the involvement of the tubulin microtubules, located beneath the plasma membrane, remains unclear. Here we show that the microtubule disrupting agent colchicine reduced Ca(2+) entry stimulated by low concentrations (0.1 U/mL) of thrombin, which activates SOCE mostly by depleting acidic Ca(2+)-store. Consistently, colchicine reduced SOCE activated by 2,5 di-(tertbutyl)-1,4-hydroquinone (TBHQ), which selectively depletes the acidic Ca(2+) stores. In contrast, colchicine enhanced SOCE mediated by depletion of the DTS, induced by high concentrations of thapsigargin (TG), which depletes both the acidic Ca(2+) stores and the DTS, the major releasable Ca(2+) store in platelets. These findings were confirmed by using Sr(2+) as a surrogate for Ca(2+) entry. Colchicine attenuated the coupling between IP(3)RII and hTRPC1 stimulated by thrombin while it enhanced that evoked by TG. Paclitaxel, which induces microtubular stabilization and polymerization, exerted the opposite effects on thrombin- and TG-evoked SOCE and coupling between IP(3)RII and hTRPC1 compared with colchicine. Neither colchicine nor paclitaxel altered the ability of platelets to extrude Ca(2+). These findings suggest that tubulin microtubules play a dual role in SOCE, acting as a barrier that prevents constitutive SOCE regulated by DTS, but also supporting SOCE mediated by the acidic Ca(2+) stores.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0898-6568
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2147-54
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Dual role of tubulin-cytoskeleton in store-operated calcium entry in human platelets.
pubmed:affiliation
Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, Downing Site, UK. pcr@unex.es
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't