Journal: The Journal of Cell Biology
Article Title: An ATM–Chk2–INCENP pathway activates the abscission checkpoint
doi: 10.1083/jcb.202008029
Figure Lengend Snippet: Mutation of Ser91 to alanine does not impair INCENP-association with CPC proteins. (A) Frequency of midbody stage cells. BE cells were released from a prometaphase block and treated with 10 µM Chk2 inhibitor II (inhII) in cytokinesis, or left untreated. Values represent mean ± SD from three independent experiments ( n > 900). (B) Accumulation of dead BE cells with time as determined by trypan blue staining. Mean ± SD from three independent experiments ( n = 6). (A and B) ***, P < 0.001 (ANOVA and Student’s t test). (C, D, G, and H) Localization of Mklp2 or Cep55 and mean intensity at the midbody or midbody center in BE cells. (E) GFP-Trap assay. BE cells were untransfected (untransf.) or transfected with GFP:INCENP. Precipitated (top) or total proteins (bottom) were analyzed by Western blotting. (F and L) Western blot analysis of total Cep55, ATM, actin and tubulin. (I) Total GFP and Mklp2 from . (J) Cartoon indicating the regions of human Mklp2 protein interacting with INCENP, Cep55 and myosin-II. Numbers show amino-acid residues. motor, kinesin motor domain. (K) Western blot analysis of total Mklp2 and actin in BE cells expressing GFP:Mklp2(ΔC90). (M) Specificity of the anti-phospho-ATM-Ser1981 (pATM-Ser1981) antibody. Tubulin values indicate midbody thickness. Insets show 1.6× magnification of the midbodies. (N and O) Phase-contrast live-cell microscopy analysis of HeLa tubulin:GFP cells treated with 10 µM KU-55933 in cytokinesis. Intercellular canals are shown by solid arrows. Time is from formation of an intercellular canal to canal cleavage (dotted arrows). Related to . Values represent mean ± SD from n cells. ***, P < 0.001 (Student’s t test). Scale bars, 5 µm. (P and Q) Frequency of prometaphase or bi/multinucleate BE cells. Values represent mean ± SD from three independent experiments ( n > 900). ns, not statistically significant. S, serine.
Article Snippet: Human Mre11 (a pool of three different siRNAs: 5′-CAG AAC AGA UGG CUA AUG A-3′, 5′-GUG AGG GAA UGG UCA CUA A-3′, and 5′-GUA GGG AAU UCU UCU GUU A-3′), ATM (a pool of three different siRNAs: 5′-GUA GCA ACA UAC UAC UCA A-3′, 5′-GCA ACA UAC UAC UCA AAG A-3′, and 5′-GCA ACC CAA UUA AUA UCA A-3′), Rad50 (a pool of three different siRNAs: 5′-CAA GGU UGC UCA AGA AAC A-3′, 5′-CCA ACC AAC UGA UGA AUG A-3′, and 5′-CAA CAG AAC UUG UGA ACA A-3′), and Cep55 (a pool of three different siRNAs: 5′-CUA CCG CAU UGC UUG AAC A-3′, 5′-CAG GUC CAG UUU CUU UAC A-3′, and 5′-GCA UGC UAG UGA AUC AUG U-3′) siRNAs were from Santa Cruz Biotechnology.
Techniques: Mutagenesis, Blocking Assay, Staining, TRAP Assay, Transfection, Western Blot, Expressing, Microscopy