Fyn is involved in angiotensin II type 2 receptor-induced neurite outgrowth, but not in p42/p44mapk in NG108-15 cells.

In NG108-15 cells, activation of p42/p44(mapk) is essential for induction of neurite outgrowth by angiotensin II (Ang II) type 2 receptor (AT(2)). The aim was to verify whether Fyn, a member of the Src family kinases (SFK), is involved in neurite outgrowth induced by AT(2) activation. Preincubation of cells with PP1, a general inhibitor of the SKF, decreased activation of Rap1 and p42/p44(mapk) and abolished TrkA activation by Ang II or by the AT(2) agonist, CGP42112A. NG108-15 cells were transfected with a Fyn-WT and a Fyn-DN expressing vector. Fyn-WT was sufficient to induce neurite outgrowth, although transfection with Fyn-DN abolished neurite elongation. However, the Fyn-DN form failed to affect activation of TrkA, Rap1 or p42/p44(mapk) by Ang II. Thus, although SKF activity is required to achieve AT(2)-induced activation of TrkA, Rap1 and p42/p44(mapk), Fyn is essential for AT(2) receptor-induced neurite outgrowth, but not in AT(2) signaling leading to p42/p44(mapk) activation.