FIG 9.

GSK3β acetylation at residue K15 regulates its mitochondrial localization. (A) N-terminal regions of GSK3β from different vertebrate species, showing acetylated K15 and K36 residues (in red). (B) Comparison of the N-terminal regions of GSK3β and GSK3α showing that residue K15 is present only in the β-isoform. (C) GSK3β prepared from the mitochondrial fraction of the heart lysate was assayed by Western blotting using antiacetyllysine and antibodies against the indicated proteins. (D) GSK3β null mouse embryonic fibroblasts were subjected to overexpression of different versions of GSK3β. The cytoplasmic and mitochondrial fractions of cells were prepared and analyzed by Western blotting using antibodies against the indicated proteins. Blots are representative of three separate experiments. Note that K15Q is mostly present in mitochondria and that K15R is located in the cytoplasm. H. sapiens, Homo sapiens; M. musculus, Mus musculus.