PMID- 15894173
OWN - NLM
STAT- MEDLINE
DCOM- 20050914
LR  - 20181201
IS  - 0898-6568 (Print)
IS  - 0898-6568 (Linking)
VI  - 17
IP  - 8
DP  - 2005 Aug
TI  - Ca2+-independent activation of Bruton's tyrosine kinase is required for 
      store-mediated Ca2+ entry in human platelets.
PG  - 1011-21
AB  - Store-mediated Ca(2+) entry (SMCE), which is rapidly activated by depletion of 
      the intracellular Ca(2+) stores, is a major mechanism for Ca(2+) influx. Several 
      studies have involved tyrosine kinases in the activation of SMCE, such as 
      pp60(src), although at present those involved in the early activation steps are 
      unknown. Here we report the involvement of Bruton's tyrosine kinase (Btk) in the 
      early stages of SMCE in human platelets. Cell treatment with thrombin or 
      thapsigargin (TG) plus ionomycin (Iono) results in rapid activation of Btk, which 
      was independent of rise in intracellular Ca(2+) concentration ([Ca(2+)](i)) but 
      dependent on H(2)O(2) generation. Platelet treatment with Btk inhibitors, LFM-A13 
      or terreic acid, significantly reduced TG+Iono- and thrombin-evoked SMCE. Btk was 
      rapidly activated by addition of low concentrations of H(2)O(2), whose effect on 
      Ca(2+) entry was prevented by Btk inhibitors. Our results indicate that pp60(src) 
      and Btk co-immunoprecipitate after platelet stimulation with TG+Iono, thrombin or 
      H(2)O(2). In addition, we have found that LFM-A13 impaired actin filament 
      reorganization after store depletion and agonist-induced activation of pp60(src), 
      while the inhibitor of pp60(src), a protein that requires actin reorganization 
      for its activation, did not modify Btk activation, suggesting that Btk is 
      upstream of pp60(src). We propose a role for Btk in the early steps of activation 
      of SMCE in human platelets.
FAU - Redondo, Pedro C
AU  - Redondo PC
AD  - Department of Physiology, University of Extremadura, Spain.
FAU - Ben-Amor, Nidhal
AU  - Ben-Amor N
FAU - Salido, Gines M
AU  - Salido GM
FAU - Bartegi, Aghleb
AU  - Bartegi A
FAU - Pariente, Jose A
AU  - Pariente JA
FAU - Rosado, Juan A
AU  - Rosado JA
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20041230
PL  - England
TA  - Cell Signal
JT  - Cellular signalling
JID - 8904683
RN  - 0 (Actins)
RN  - 526U7A2651 (Egtazic Acid)
RN  - 56092-81-0 (Ionomycin)
RN  - 67526-95-8 (Thapsigargin)
RN  - BBX060AN9V (Hydrogen Peroxide)
RN  - EC 2.7.10.1 (Protein-Tyrosine Kinases)
RN  - EC 2.7.10.2 (Agammaglobulinaemia Tyrosine Kinase)
RN  - EC 2.7.10.2 (BTK protein, human)
RN  - EC 2.7.10.2 (Proto-Oncogene Proteins pp60(c-src))
RN  - EC 3.4.21.5 (Thrombin)
RN  - K22DDW77C0 (1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Actins/metabolism
MH  - Agammaglobulinaemia Tyrosine Kinase
MH  - Blood Platelets/*enzymology/metabolism
MH  - Blotting, Western
MH  - Calcium/*metabolism
MH  - Cell Survival
MH  - Egtazic Acid/analogs & derivatives/pharmacology
MH  - Enzyme Activation
MH  - Humans
MH  - Hydrogen Peroxide/pharmacology
MH  - Immunoprecipitation
MH  - Ionomycin/pharmacology
MH  - Phosphorylation
MH  - Protein-Tyrosine Kinases/*chemistry
MH  - Proto-Oncogene Proteins pp60(c-src)/metabolism
MH  - Thapsigargin/metabolism
MH  - Thrombin/metabolism
MH  - Time Factors
EDAT- 2005/05/17 09:00
MHDA- 2005/09/15 09:00
CRDT- 2005/05/17 09:00
PHST- 2004/11/08 00:00 [received]
PHST- 2004/11/24 00:00 [revised]
PHST- 2004/11/25 00:00 [accepted]
PHST- 2005/05/17 09:00 [pubmed]
PHST- 2005/09/15 09:00 [medline]
PHST- 2005/05/17 09:00 [entrez]
AID - S0898-6568(04)00268-2 [pii]
AID - 10.1016/j.cellsig.2004.11.019 [doi]
PST - ppublish
SO  - Cell Signal. 2005 Aug;17(8):1011-21. doi: 10.1016/j.cellsig.2004.11.019. Epub 
      2004 Dec 30.