Figure 3: Full intra-kinetochore stretch is not required for SAC silencing in monopolar HEC1-9A cells.
From: Kinetochore–microtubule attachment is sufficient to satisfy the human spindle assembly checkpoint
(a) Cartoons illustrating the concept of kinetochore distances in attached or unattached states. Relative to unattached chromosomes (upper drawing), sister kinetochores of bioriented chromosomes (bottom drawing) are positioned further away from one another and experience stretch within individual kinetochores. (b,c) Representative images (b) and quantification (c; average of three experiments±s.e.m.) of the distance between HEC1(N) and CENP-C in fixed cells (illustration in c). Cells were treated with nocodazole or STLC before mitotic entry, after which they were treated with MG132 for 2 h before fixation. At least 147 kinetochores were measured for each mutant. Scale bar, 5 μm. Scale bar inset, 1 μm (d) Quantification (upper panel) and representative images (lower panel) of time-lapse single-cell analysis of bipolar control cells or monopolar HEC1-9A cells expressing RFP-MAD2. Cells were released from RO and imaging was initiated after mitotic entry. Note that MAD2 is overexpressed in these cells. Data are the average of two experiments±s.d. Quantifications were subjected to unpaired Student’s t-test against the values measured for control cells. *P<0.01. Scale bar, 10 μm.
