Mitogen-activated protein kinase kinases promote mitochondrial biogenesis in part through inducing peroxisome proliferator-activated receptor γ coactivator-1β expression

► Mitochondrial mass is reduced by withdrawing serum and MEK1/2 inhibitor U0126. ► MEK1 or MEK2 over-expression induces mitochondrial biogenesis. ► U0126 specifically suppresses mitochondrial regulator PGC-1β expression. ► PGC-1β over-expression blunts the U0126-mediated mitochondrial mass reduction. ► MEK-ERK cascade directs mitochondrial biogenesis by inducing PGC-1β expression.