TABLE 1.

Effect of TPPP/p25 on the acetylation level of microtubules modulated by the inhibitor of HDAC6

HeLa cells transiently transfected with the pEGFP-TPPP/p25 were treated with 10 nm or 500 nm TSA (HDAC6 inhibitor). After overnight incubation, the cells were immunostained for acetylated tubulin. The fluorescence signal of individual cells was quantified to obtain the acetylation level and expressed relative to the degree of acetylation observed for control cells (100%). The status of the microtubules (normal, bundled, or depolymerized) was also determined. Values are shown ± S.E. n (control) = 63, n (10 nm TSA) = 121, n (500 nm TSA) = 36, n (TPPP/p25) = 43, n (TPPP/p25 + 500 nm TSA) = 21, n (TPPP/p25 + 10 nm TSA) = 39. These data are representative of three independent experiments.

	Acetylation level	Microtubules	Cold/nocodazole treatment	Cold/nocodazole treatment after TSA treatment
	%
Control	100 ± 12	Normal	Depolymerized	Depolymerized
10 nm TSA	256 ± 9a	Normal	Depolymerized	Depolymerized
500 nm TSA	487 ± 16a	Normal	Depolymerized	Depolymerized
TPPP/p25	170 ± 15a	Bundled	Bundled	Bundled
TPPP/p25 + 10 nm TSA	534 ± 16a	Bundled	Bundled	Bundled
TPPP/p25 + 500 nm TSA	490 ± 21a	Bundled	Bundled	Bundled

^a Significant difference in the level of acetylated tubulin between drug treated/transfected cells and control cells (according to Student's t test, p < 0.05).