Page 242 - Veterinary Immunology, 10th Edition

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FIG. 8.12 Signal transduction by two cross-linked BCRs activates
B cells, triggering cell division, differentiation, and immunoglobulin
synthesis. Both NF-κB and NF-AT are involved in B cell signal
transduction.

AP-1 belongs to a family of transcription factors consisting of fos
and jun heterodimers. Production of AP-1 is also triggered by the
proximal signaling complex (PSC). The PSC activates a protein
kinase C, which in turn leads to activation of ras-mitogen protein

kinase (MAPK) and increased production of c-fos. The c-fos moves
to the nucleus, where it combines with preexisting jun proteins to
form AP-1. AP-1 binds to NF-AT proteins integrating the calcium
signaling with the ras-MPCK pathway. Collectively they activate

the genes coding for IL-2, IFN-γ, GM-CSF, TNF-α, IL-3, IL-4, IL-13,
IL-5, FasL, and CD25.

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