While beta 2 integrin ligand-receptor recognition interactions are well characterized, less is known about how these events trigger signal transduction cascades to regulate the transition from tethering to firm adhesion, spreading, and transendothelial migration. We have identified critical positive and negative regulatory components of this cascade in monocytes. Whereas the Syk tyrosine kinase is essential for beta 2 integrin signaling and cell spreading, the Src family kinase Fgr is a negative regulator of this pathway. Fgr selectively inhibits beta 2 but not beta 1 integrin signaling and Syk kinase function via a direct association between the Fgr SH2 domain and Syk tyrosine Y342. The inhibitory effects of Fgr are independent of its kinase activity, are dose dependent, and can be overcome by chemokines and inflammatory mediators.
SciCrunch is a data sharing and display platform. Anyone can create a custom portal where they can select searchable subsets of hundreds of data sources, brand their web pages and create their community. SciCrunch will push data updates automatically to all portals on a weekly basis. User communities can also add their own data to SciCrunch, however this is not currently a free service.