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SLP-65: a new signaling component in B lymphocytes which requires expression of the antigen receptor for

J Wienands1, J Schweikert, B Wollscheid

  • 1Department for Molecular Immunology, Biology III, University of Freiburg, 79104 Freiburg, Germany. wienanands@immunbio.mpg.de

The Journal of Experimental Medicine
|August 26, 1998
PubMed

Insights

Researchers identified SLP-65, a B cell adaptor protein, as a key early component in B cell receptor (BCR) signaling. This protein is phosphorylated upon BCR expression, indicating its role in BCR signal transduction.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cell Signaling

Background:

  • The B cell antigen receptor (BCR) complex initiates signaling cascades upon antigen binding.
  • BCR signal transduction involves protein tyrosine kinases (PTKs) and the phosphorylation of various downstream substrates.
  • Identifying these substrates is crucial for understanding B cell activation.

Purpose of the Study:

  • To identify early signaling substrates involved in B cell receptor (BCR) signal transduction.
  • To characterize a specific 65-kD protein identified as an early substrate.

Main Methods:

  • Stimulation of B cells with the tyrosine phosphatase inhibitor pervanadate/H2O2.
  • Analysis of protein phosphorylation patterns.
  • Identification of signaling complex components through association studies.

Main Results:

  • A 65-kD B cell adaptor protein, named SLP-65, was identified as an early substrate in BCR signaling.
  • SLP-65 forms a signaling complex with Grb-2 and Vav.
  • SLP-65 phosphorylation is dependent on BCR expression and occurs upon stimulation.

Conclusions:

  • SLP-65 is a novel component of the B cell receptor (BCR) transducer complex.
  • Its phosphorylation upon BCR engagement suggests a critical role in propagating signals initiated by the BCR.
  • SLP-65 is homologous to SLP-76, a known T cell receptor signaling element, highlighting conserved signaling mechanisms.

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