Tubulin Tyrosine Ligase Like Protein 7 (TTLL7)

TTLL7 was transcribed at the highest level in the nervous system.TTLL7 demonstrated specificity for β-tubulin and not for α-tubulin or nucleosome assembly protein 1. Consistent with these findings, knockdown of TTLL7 in a primary culture of superior cervical ganglion neurons caused a loss of polyglutamylated β-tubulin. Following stimulation of PC12 cells with nerve growth factor to differentiate, the level of TTLL7 increased concomitantly with polyglutamylation of β-tubulin. TTLL7 accumulated within a MAP2-enriched somatodendritic portion of superior cervical ganglion, as did polyglutamylated β-tubulin. TTLL7 was distributed in a somatodendritic compartment in the mouse brain. TTLL7 is a β-tubulin polyglutamylase and is required for the growth of MAP2-positive neurites in PC12 cells.