Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 1 (VEGFR-1); member of the I-set of Ig superfamily (IgSF) domains
The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 1 (VEGFR-1). VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGFR-1 binds VEGF-A strongly; VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGFR-1 may play an inhibitory role in the function of VEGFR-2 by binding VEGF-A and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis and may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.