FIGURE 3.

α-Tubulin processing in HEK293T cells after CCP1 overexpression or knockdown. A, representative Western blots for CCP1 protein and different forms of α-tubulin in HEK293T cells after overexpression of His₆-tagged CCP1. B, densitometric analysis of the levels of CCP1 protein and different tubulin forms in control and CCP1-overexpressing HEK293T cells. The Tyr-, deTyr-, and delta2-tubulin band densities were normalized with the corresponding α-tubulin bands. Band densities were measured using the Odyssey infrared imaging system. The levels of delta2-tubulin are significantly increased in HEK293T cells after CCP1 overexpression for 2 days, whereas other tubulin modifications are not affected. Error bars represent mean ± S.E. (n = 4). **, p < 0.01 using Student's t test. C, representative Western blots for CCP1 protein and different forms of α-tubulin after treatment of cells with CCP1 siRNA for 3 days. D, densitometric analysis of the levels of CCP1 protein and different tubulin forms in control and siRNA-treated HEK293T cells. The Tyr-, deTyr-, and delta2-tubulin band densities were normalized with the corresponding α-tubulin bands. The levels of delta2-tubulin are significantly decreased in HEK293T cells after CCP1 mRNA knock down for 3 days. Error bars represent mean ± S.E. (n = 4). **, p < 0.01 using Student's t test. Abbreviations used are as follows: c, control; KD, knockdown; ovx, overexpression; Tub, tubulin.