PMID- 10051622
OWN - NLM
STAT- MEDLINE
DCOM- 19990415
LR  - 20200304
IS  - 0027-8424 (Print)
IS  - 0027-8424 (Linking)
VI  - 96
IP  - 5
DP  - 1999 Mar 2
TI  - In situ detection of activated Bruton's tyrosine kinase in the Ig signaling
      complex by phosphopeptide-specific monoclonal antibodies.
PG  - 2221-6
AB  - Bruton's tyrosine kinase (Btk) is a critical transducer of signals originating
      from the B cell antigen receptor (BCR). Dosage, sequential phosphorylation, and
      protein interactions are interdependent mechanisms influencing Btk function.
      Phosphopeptide-specific mAbs recognizing two distinct phosphotyrosine
      modifications were used to quantify Btk activation by immunofluorescent
      techniques during B cell stimulation. In a population of cultured B cells
      stimulated by BCR crosslinking and analyzed by flow cytometry, transient
      phosphorylation of the regulatory Btk tyrosine residues (551Y and 223Y) was
      detected. The kinetics of phosphorylation of the residues were temporally
      distinct. Tyrosine 551, a transactivating substrate site for Src-family kinases, 
      was maximally phosphorylated within approximately 30 seconds of stimulation as
      monitored by flow cytometry. Tyrosine 223, an autophosphorylation site within the
      SH3 domain, was maximally phosphorylated at approximately 5 minutes. Btk returned
      to a low tyrosine phosphorylation level within 30 minutes, despite persistent
      elevation of global tyrosine phosphorylation. Colocalization of activated Btk
      molecules with the crosslinked BCR signaling complex was observed to coincide
      with the period of maximal Btk tyrosine phosphorylation when stimulated B cells
      were analyzed with confocal microscopy. The results of these in situ temporal and
      spatial analyses imply that Btk signaling occurs in the region of the Ig receptor
      signaling complex, suggesting a similar location for downstream targets of its
      activity.
FAU - Nisitani, S
AU  - Nisitani S
AD  - Department of Howard Hughes Medical Institute, University of California, Los
      Angeles, CA 90095, USA.
FAU - Kato, R M
AU  - Kato RM
FAU - Rawlings, D J
AU  - Rawlings DJ
FAU - Witte, O N
AU  - Witte ON
FAU - Wahl, M I
AU  - Wahl MI
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - 0 (Antibodies, Monoclonal)
RN  - 0 (Immunoglobulin G)
RN  - 0 (Phosphopeptides)
RN  - 0 (Receptors, IgG)
RN  - 0 (Recombinant Proteins)
RN  - 21820-51-9 (Phosphotyrosine)
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 (Btk protein, mouse)
RN  - EC 2.7.10.2 (src-Family Kinases)
SB  - IM
MH  - Agammaglobulinaemia Tyrosine Kinase
MH  - Amino Acid Sequence
MH  - Amino Acid Substitution
MH  - Animals
MH  - Antibodies, Monoclonal
MH  - Antibody Specificity
MH  - B-Lymphocytes/enzymology/*immunology
MH  - Flow Cytometry
MH  - Humans
MH  - Immunoglobulin G/metabolism
MH  - Immunohistochemistry
MH  - Kinetics
MH  - Lymphocyte Activation
MH  - Mice
MH  - Mice, Inbred BALB C
MH  - Molecular Sequence Data
MH  - Mutagenesis, Site-Directed
MH  - Phosphopeptides/*analysis/immunology
MH  - Phosphorylation
MH  - Phosphotyrosine/analysis
MH  - Protein-Tyrosine Kinases/*metabolism
MH  - Receptors, IgG/*physiology
MH  - Recombinant Proteins/metabolism
MH  - Signal Transduction
MH  - Substrate Specificity
MH  - Transfection
MH  - src Homology Domains
MH  - src-Family Kinases/metabolism
PMC - PMC26764
EDAT- 1999/03/03 00:00
MHDA- 1999/03/03 00:01
CRDT- 1999/03/03 00:00
PHST- 1999/03/03 00:00 [pubmed]
PHST- 1999/03/03 00:01 [medline]
PHST- 1999/03/03 00:00 [entrez]
AID - 10.1073/pnas.96.5.2221 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 1999 Mar 2;96(5):2221-6. doi: 10.1073/pnas.96.5.2221.