Fig. 7. Y654-P β-catenin colocalizes with the neuronal cytoskeleton and Y142-P β-catenin is found in the nucleus. (A) Double immunostaining for endogenous β-catenin and F-actin (phalloidin) in hippocampal neurons shows that β-catenin and F-actin partially colocalize (arrows) at neurite tips and lamella (inset). (B) Confocal image of hippocampal neurons fixed using detergent fixation shows the double immunostaining for Y654-P β-catenin and βIII-tubulin that colocalize at enlarged growth cones where microtubules unbundle and along the axon (arrows). Y654-P β-catenin immunostaining can also be observed along filopodial-like processes and axonal-spread areas devoid of βIII-tubulin (arrowheads). (C) Confocal image of neurons fixed by detergent fixation shows the double immunostaining for Y654-P β-catenin and F-actin (phalloidin). Similar to anti-β-catenin antibodies, anti-Y654-P-β-catenin antibodies stain the cell body and neurite tips, where Y654-P β-catenin and F-actin colocalize (arrows). (D) β-catenin and Y142-P β-catenin colocalize within the cytoplasm of neurons (arrows), whereas colocalization of Hoestch and anti-Y142-P-β-catenin immunostaining shows that Y142-P β-catenin is found in the nucleus (arrowheads). (E) Anti-Y654-P-β-catenin antibodies stain the cell membrane at cell contacts and the cytoplasm, but the nucleus (stained by Hoestch) is negative. Scale bars: 15 µm (A), 20 µm (B,C) and 45 µm (D,E).