The Ig alpha/Igbeta heterodimer on mu-negative proB cells is competent for transducing signals to induce early B cell differentiation.
The immunoglobulin alpha (Ig alpha)/Ig beta heterodimer was detected on the surface of mu-negative proB cell lines in association with calnexin. The cross-linking of Ig beta on proB cells freshly isolated from bone marrow of recombination activating gene (RAG)-2-deficient mice induced a rapid and transient tyrosine-phosphorylation of Ig alpha as well as an array of intracellular proteins including Syk, PI3-kinase, Vav, and SLP-76. It also elicited the phosphorylation and activation of a MAP kinase ERK but not JNK/SAPK or p38. When RAG-2-deficient mice were treated with anti-Ig beta monoclonal antibody, developmentally arrested proB cells were induced to differentiate to the small preB cell stage as observed when the mu transgene was expressed in RAG-2-deficient mice. Thus, the cross-linking of Ig beta on proB cells appears to elicit differentiation signals analogous to those delivered by the preB cell receptor in normal B cell development.
Nagata
K
K
Department of Immunology, The Tokyo Metropolitan Institute of Medical Science, Japan.
Nakamura
T
T
Kitamura
F
F
Kuramochi
S
S
Taki
S
S
Campbell
K S
KS
Karasuyama
H
H
D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology; D001854:Bone Marrow Cells / Q000166:cytology; D051925:CD79 Antigens; D002135:Calcium-Binding Proteins / Q000502:physiology; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D037281:Calnexin; D002454:Cell Differentiation; D002462:Cell Membrane / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000502:physiology; D019281:Dimerization; D007148:Immunoglobulin mu-Chains; D019891:Leukopoiesis; D051379:Mice; D018345:Mice, Knockout; D008822:Mice, Transgenic; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D019000:Phosphotyrosine / Q000378:metabolism; D011494:Protein Kinases / Q000502:physiology; D011940:Receptor Aggregation; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D015398:Signal Transduction
D015703:Antigens, CD; D051925:CD79 Antigens; D002135:Calcium-Binding Proteins; C497882:Cd79a protein, mouse; C497884:Cd79b protein, mouse; D004268:DNA-Binding Proteins; D007148:Immunoglobulin mu-Chains; C499308:Rag2 protein, mouse; D011947:Receptors, Antigen, B-Cell; C064655:V(D)J recombination activating protein 2; D037281:Calnexin; D019000:Phosphotyrosine; D011494:Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases