B. Brenner et al., L-selectin tyrosine phosphorylates Cbl and induces association of tyrosine-phosphorylated Cbl with CrkL and Grb2, BIOC BIOP R, 282(1), 2001, pp. 41-47
Citations number
34
Categorie Soggetti
Biochemistry & Biophysics
Journal title
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
L-Selectin-mediated rolling of leukocytes on endothelial cells is an import
ant step for lymphocyte homing and an early event in the immune response to
pathogens or inflammatory stimuli. We have previously elucidated intracell
ular signaling cascades upon L-selectin engagement resulting in activation
of Has, Rac and JNK as well as cytoskeletal changes, oxygen release, cerami
de synthesis and receptor capping. Activation of the src-tyrosine kinase p5
6lck is followed by phosphorylation of the L-selectin molecule and MAP-K. H
ere we show a tyrosine kinase dependent phosphorylation of the Cbl adapter
protein after L-selectin engagement in lymphocytes. Phosphorylation of Cbl
was absent in Jurkat cells that are pharmacologically treated with tyrosine
kinase inhibitors and in lck-deficient JCaM cells. There is an activation
induced association of tyrosine phosphorylated Cbl with Grb2 and CrkL, resp
ectively, but not CrkII. Therefore, the adapter protein Cbl plays a role in
L-selectin signaling and might modulate immune function by the specific re
cruitment of signaling molecules to multiprotein complexes. (C) 2001 Academ
ic Press.