Core fucosylation of μ heavy chains regulates assembly and intracellular signaling of precursor B cell receptors

J Biol Chem. 2012 Jan 20;287(4):2500-8. doi: 10.1074/jbc.M111.303123. Epub 2011 Nov 14.


α1,6-Fucosyltransferase (Fut8) knock-out (Fut8(-/-)) mice showed an abnormality in pre-B cell generation. Membrane assembly of pre-BCR is a crucial checkpoint for pre-B cell differentiation and proliferation in both humans and mice. The assembly of pre-BCR on the cell surface was substantially blocked in the Fut8-knockdown pre-B cell line, 70Z/3-KD cells, and then completely restored by re-introduction of the Fut8 gene to 70Z/3-KD (70Z/3-KD-re) cells. Moreover, loss of α1,6-fucosylation (also called core fucosylation) of μHC was associated with the suppression of the interaction between μHC and λ5. In contrast to Fut8(+/+) CD19(+)CD43(-) cells, the subpopulation expressing the μHC·λ5 complex in the Fut8(-/-) CD19(+)CD43(-) cell fraction was decreased. The pre-BCR-mediated tyrosine phosphorylation of CD79a and activation of Btk were attenuated in Fut8-KD cells, and restored in 70Z/3-KD-re cells. The frequency of CD19(low)CD43(-) cells (pre-B cell enriched fraction) was also reduced in Fut8(-/-) bone marrow cells, and then the levels of IgM, IgG, and IgA of 12-week-old Fut8(-/-) mice sera were significantly lower than those of Fut8(+/+) mice. Our results suggest that the core fucosylation of μHC mediates the assembly of pre-BCR to regulate pre-BCR intracellular signaling and pre-B cell proliferation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Fucose / genetics
  • Fucose / immunology
  • Fucose / metabolism*
  • Fucosyltransferases / genetics
  • Fucosyltransferases / immunology
  • Fucosyltransferases / metabolism*
  • Glycosylation
  • Immunoglobulin A / genetics
  • Immunoglobulin A / immunology
  • Immunoglobulin A / metabolism
  • Immunoglobulin G / genetics
  • Immunoglobulin G / immunology
  • Immunoglobulin G / metabolism
  • Immunoglobulin M / genetics
  • Immunoglobulin M / immunology
  • Immunoglobulin M / metabolism
  • Immunoglobulin lambda-Chains / genetics
  • Immunoglobulin lambda-Chains / immunology
  • Immunoglobulin lambda-Chains / metabolism
  • Immunoglobulin mu-Chains / genetics
  • Immunoglobulin mu-Chains / immunology
  • Immunoglobulin mu-Chains / metabolism*
  • Mice
  • Mice, Knockout
  • Precursor Cells, B-Lymphoid / immunology
  • Precursor Cells, B-Lymphoid / metabolism*
  • Receptors, Antigen, B-Cell / genetics
  • Receptors, Antigen, B-Cell / immunology
  • Receptors, Antigen, B-Cell / metabolism*
  • Signal Transduction / physiology*


  • Immunoglobulin A
  • Immunoglobulin G
  • Immunoglobulin M
  • Immunoglobulin lambda-Chains
  • Immunoglobulin mu-Chains
  • Receptors, Antigen, B-Cell
  • Fucose
  • Fucosyltransferases
  • Glycoprotein 6-alpha-L-fucosyltransferase