Discrete States of a Protein Interaction Network Govern Interphase and Mitotic Microtubule Dynamics
Figure 3
Change in the MAP Interaction Network at Interphase/Metaphase Transition
(A) Pairwise interaction of MAPs in interphase and metaphase are represented as color-coded tables (upper panel). The color code corresponds to <IVIP> of at least three different microscopic fields. Proteins in green are EGFP tagged, and those in blue are Cy5 labeled. Below each table is a schematic representation of the network states in interphase and metaphase. Line thickness corresponds to interaction strength normalized to the strongest signal detected in interphase or metaphase. In the lower panel, an interphase aster is shown on the left and a mitotic one on the right
(B) CDK1 activity induced a change in EB1-APCMTBD and EB1-XMAP215 interactions. EB1-EGFP fluorescence was measured simultaneously on beads coated with anti-XMAP215 and anti-APCMTBD antibodies in the presence of APCMTBD, and added to metaphase, interphase, and interphase extracts after addition of active, purified CDK1. Error bars represent the s.e.m. of <Ivip> measured in six different microscopic fields. A.U., arbitrary units.
(C) XMAP215/EB1-EGFP interaction in metaphase (open bars) and XMAP215/XKCM1-EGFP and APCMTBD/EB1-EGFP interaction in interphase (filled bars) before (control) and after incubation with 10 μM okadaic acid (OA). Error bars represent the s.e.m. of <IVIP> derived from at least three different microscopic fields.