Coexpression of hFis1 and Pex11pβ influences the intracellular distribution of peroxisomes. COS-7 cells were cotransfected with Mito-GFP and Pex11pβ-Myc (A and B), with Mito-GFP and untagged hFis1(hFis1-UT) (C and D), with Mito-GFP, Pex11pβ-Myc and untagged hFis1(hFis1-UT) (E and F), or with GFP-hFis1 and Pex11pβ-Myc (G and H). Twenty-four hours after transfection, cells were immunostained with anti-Myc (B, F, and H) or anti-PMP70 (D) antibodies. Note the juxtanuclear clustering of peroxisomes and their association with mitochondria in cells coexpressing hFis1 and Pex11pβ (E–H). N, nucleus. Bars, 10 μm.