Baff receptor

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Baff receptor

Existing structural data : 1p0t

Properties of human protein
Mass / length primary structure 184 amino acids
Secondary to quaternary structure Membrane protein
Isoforms 2
Identifier
Gene name TNFRSF13C
External IDs
Occurrence
Parent taxon Mammals

The BAFF receptor (BAFF-R) is a membrane protein in the B-cells of mammals . It is the most important receptor for the cytokine Baff and, alongside the B-cell receptor, the most important receptor for conveying survival signals in B-cells. The receptor is expressed on mature B cells expressed . Its expression is upregulated in the course of B cell development. This happens at the transition stage, when immature B cells become mature B cells. Mutations in TNFRSF13C - gene can in humans to a congenital immunodeficiency lead (CVID4).

Signal conduction through the Baff receptor

The stimulation of the Baff receptor leads to the activation of the alternative NF-κB signaling pathway (NF-κB2). NF-κB1 is also weakly activated by the Baff receptor. However, this is more strongly influenced by TACI, a receptor that also binds Baff.

The Baff receptor also binds to TRAF3, which interacts with the kinase NIK ( NF-κB inducing kinase ). TRAF3 induces the degradation of NIK, which results in a reduced NF-κB2 activity. Therefore, at first glance, this interaction contradicts the activation of NF-κB2 by the Baff receptor. A possible model that would clarify this contradiction is a degradation of TRAF3 through the binding of Baff to the Baff receptor. This would stabilize NIK and activate the alternative NF-κB2 signaling pathway. In a way that was not previously understood, Baff also activates PI3K and thus protein kinase B (also AKT). The activation of this kinase in turn leads to the activation of Mcl-1 on the one hand and mTOR on the other hand and thus the mTORC1 complex. The mTORC1 complex is important for protein synthesis, Mcl-1 is a member of the Bcl-2 family and ensures the survival of B cells and T cells.

BAff receptor deficiency in mice

Mice that are deficient for the Baff receptor show a similar phenotype to mice that are deficient for the cytokine Baff . Among other things, the animals lack most of the peripheral B cells.

Individual evidence

  1. ↑ Orthologist at OMA
  2. ↑ UniProt Q96RJ3
  3. ^ Fabienne Mackay, William A. Figgett, Damien Saulep, Melanie Lepage, Margaret L. Hibbs: B-cell stage and context-dependent requirements for survival signals from BAFF and the B-cell receptor . In: Immunological Reviews . tape 237 , no. 1 , September 2010, p. 205–225 , doi : 10.1111 / j.1600-065X.2010.00944.x .