Supplemental Figure 1 XMCAK-4A associates with ICIS in Xenopus extract. IgG and anti-ICIS immunoprecipitates from mock-depleted, MCAK-depleted (ΔMCAK), and MCAK-depleted extracts supplemented with either wt XMCAK or XMCAK-4A were analyzed by immunoblotting using either anti-ICIS or anti-XMCAK antibodies.