Figure 7: NCAM and PSA-NCAM signaling pathways. Currently accepted signaling pathways believed to be involved in neurite outgrowth; the most studied and understood result of NCAM activation. NCAM-180 and- 140 are represented by five Ig like domains and two fibronectin III domains extracellularly and an intracellular segment of varying length. NCAM-120 is attached to the membrane via a GPI anchor. Color designations: tyrosine kinases = red; other protein kinases = blue; nonproteins = silver. Abbreviations: AA, arachidonic acid; cAMP, cyclic adenosine monophosphate; CREB, cAMP response element-binding protein; CaMK, Ca2+-calmodulin-dependent kinase; cGMP, cyclic guanosine monophosphate; CKII, casein kinase II; DAG, diacylglycerol; ERK, extracellular regulated kinase; FAK, focal adhesion kinase; FGFR, fibroblast growth factor receptor; Frs2, FGFR substrate; GAP-43, growth-associated protein 43; NO, nitric oxide; NOS, NO synthase; NSCC, nonspecific cation channel; PI3K, phosphatidylinositol 3-kinase; PKA, protein kinase A; PKC, protein kinase C; PKG, protein kinase G; PLC, phospholipase C; RPTP, receptor protein tyrosine phosphatase; VDCC, voltage-dependent Ca2+-channel. Broken lines indicate putative intracellular interactions. Illustration adapted with permission from [18, 38].