Figure 2. L-selectin-triggered intracellular signaling in leukocytes.

L-selectin binding to ligands causes selectin clustering, which induces receptor tyrosine and serine phosphorylation and activation of the ERM proteins. This leukocyte activation further results in: 1 integrin activation through MAPK kinase; 2 leukocyte degranulation, particularly by neutrophils; 3 activation of the ras pathway; 4 L-selectin shedding, which modulates immune responsiveness of leukocytes.