C, DN‐terminal region of CAMDI recognizes the second HDAC domain of HDAC6. SH‐SY5Y cells were co‐transfected with HDAC6‐HA and each FLAG‐CAMDI fragment (C) (fragment 1, 1–250; 2, 251–500; 3, 501–750; 4, 751–1,000; 5, 1,001–1,451 amino acids) or co‐transfected with FLAG‐CAMDI and each HDAC6‐HA fragment (D) (fragment 1 (DD1), 1–440; 2 (DD2), 441–840; 3, 841–1,215 amino acids). Co‐IP assay was performed with the indicated antibodies. n = 3 independent experiments. **P < 0.01, ***P < 0.001; one‐way ANOVA with Bonferroni's post hoc test. Data are presented as mean ± SEM.