The molecular mechanism of B cell activation by toll-like receptor protein RP-105.
The B cell-specific transmembrane protein RP-105 belongs to the family of Drosophila toll-like proteins which are likely to trigger innate immune responses in mice and man. Here we demonstrate that the Src-family protein tyrosine kinase Lyn, protein kinase C beta I/II (PKCbetaI/II), and Erk2-specific mitogen-activated protein (MAP) kinase kinase (MEK) are essential and probably functionally connected elements of the RP-105-mediated signaling cascade in B cells. We also find that negative regulation of RP-105-mediated activation of MAP kinases by membrane immunoglobulin may account for the phenomenon of antigen receptor-mediated arrest of RP-105-mediated B cell proliferation.
Chan
V W
VW
Department of Laboratory Medicine, University of California, San Francisco, California 94143, USA.
Mecklenbräuker
I
I
Su
I
I
Texido
G
G
Leitges
M
M
Carsetti
R
R
Lowell
C A
CA
Rajewsky
K
K
Miyake
K
K
Tarakhovsky
A
A
D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology*; D002118:Calcium / Q000378:metabolism; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D029721:Drosophila Proteins; D004789:Enzyme Activation / Q000276:immunology; D005434:Flow Cytometry; D007075:Immunoglobulin M / Q000276:immunology; D008562:Membrane Glycoproteins / Q000276:immunology / Q000502:physiology*; D008565:Membrane Proteins / Q000276:immunology; D051379:Mice; D018345:Mice, Knockout; D020929:Mitogen-Activated Protein Kinase Kinases; D010766:Phosphorylation; D011493:Protein Kinase C / Q000502:physiology; D011494:Protein Kinases / Q000502:physiology; D011956:Receptors, Cell Surface / Q000276:immunology / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D013154:Spleen / Q000276:immunology; D051193:Toll-Like Receptors; D019061:src-Family Kinases / Q000502:physiology
D029721:Drosophila Proteins; D007075:Immunoglobulin M; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D051193:Toll-Like Receptors; D011494:Protein Kinases; D019061:src-Family Kinases; D011493:Protein Kinase C; D020929:Mitogen-Activated Protein Kinase Kinases; D002118:Calcium