MNAR–ER–Src interaction leads to Src activation. (A) MNAR structure-functional organization. (B) Proposed model of ER–MNAR–Src interaction. (C) Analysis of c-Src enzymatic activity. The c-Src tyrosine kinase activity was evaluated in the absence (lanes 1 and 2) or presence (lanes 3–6) of ERα, E2 (at 1 μM, lanes 3 and 5), and MNAR (lanes 2, 5, and 6) by using acidified enolase as a substrate.