ttl是一種參與α-微管蛋白翻譯后修飾的胞漿酶（見mim 602529）。聚集微管內的α-微管蛋白隨著時間在C末端被去甲狀腺激素化微管解體后，TTL恢復酪氨酸殘基，從而參與微管蛋白去酪氨酸酶和酪氨酸酶的循環（ERCK等人，2003【PubMed 14571137】。
TTL is a cytosolic enzyme involved in the posttranslational modification of alpha-tubulin (see MIM 602529). Alpha-tubulin within assembled microtubules is detyrosinated over time at the C terminus. After microtubule disassembly, TTL restores the tyrosine residues and consequently participates in a cycle of tubulin detyrosination and tyrosination (Erck et al., 2003 [PubMed 14571137]).