Fig. 8: AnkB recruits Drp1 to mitochondria in SKM to promote efficient fission.
a Drp1’s subcellular localization and GTP-ase activity are modulated by phosphorylation. Western blot (b) and quantification (c) of Drp1 (total), pDrp1S579/Drp1-total (S616 in humans), and pDrp1S600/Drp1-total (S637 in humans) levels in GC and SOL lysates from 4-mo mice (GC: n = 5 WT, n = 8 AnkB-KO mice; SOL n = 5 WT, n = 6 AnkB-KO mice). d Representative images of pDrp1S579 localization in FDB fibers from 4-mo mice co-stained with the OMM marker Tom20. Scale bar, 5 µm. Insets show higher magnification of the yellow dotted boxed regions. Scale bar, 1 µm. e–g pDrp1S579 colocalization with mitochondria measured using overlap coefficient (n = 3 mice/genotype). Data in e was collected from n = 47 WT and n = 44 AnkB-KO fibers. Data in f, g was collected from n = 27 WT and n = 23 AnkB-KO fibers. h, i. Per volume number (h) and volume (i) of pDrp1S579 puncta (n = 3 mice/genotype). Data in h was collected from n = 37 WT and n = 35 AnkB-KO fibers. Data in i was collected from n = 42 WT and n = 32 AnkB-KO fibers. j Representative images of pDrp1S579 and MFF localization in FDB fibers. Scale bar, 5 µm. Insets show higher magnification of yellow dotted boxed regions. Scale bar, 1 µm. k pDrp1S579 colocalization with MFF measured using overlap coefficient (n = 3 mice/genotype; n = 12 WT and n = 11 AnkB-KO fibers). Western blot (l) and quantification of MFF (m) and Drp1 (n) monomers and higher order species in either native (−DTT) or reduced (+DTT) lysates from 4-mo SOL (n = 3 WT, n = 4 KO mice). Data show mean ± S.D. Statistical differences were determined by single or multiple two-tailed unpaired t-test with a significance threshold of p < 0.05.
