Disease relevance of Ttl

• RESULTS: No catch up in body weight (BW; p < .05), total length (TTL; p < .001), or tail length (TL; females, p < .02; males, p < .001) was observed in the adult female and male FR rats [1].

High impact information on Ttl

• The sequence of tubulin-tyrosine ligase (TTL), the enzyme catalyzing the ATP-dependent posttranslational addition of a tyrosine to the carboxyterminal end of detyrosinated alpha-tubulin, has been determined [2].
• TTL contains a potential serine phosphorylation site for cAMP-dependent protein kinase (RKAS at positions 73 to 76) [2].
• A post-translational modification of tubulin with potential regulatory significance has been revealed by the discovery of an enzyme (tubulin-tyrosine ligase) in brain extracts which can add a tyrosine residue to the alpha chain, apparently through peptide bond linkage to a C-terminal glutamate [3].
• The release of the incorporated amino acid was measured by using tubulinyl-tyrosine carboxypeptidase, carboxypeptidase A, and tubulin-tyrosine ligase [4].
• Cloning of rat olfactory bulb tubulin tyrosine ligase cDNA: a dominant negative mutant and an antisense cDNA increase the proliferation rate of cells in culture [5].

Biological context of Ttl

• Comparison of the deduced amino acid sequence of rat TTL cDNA with those of bovine and pig showed approximately 90% of identity [5].
• These results support the hypothesis that TTL may play a role in the regulation of the cell cycle in living cells [5].
• Transient transfection of CHO-K1 cells with a dominant negative mutant of TTL that contains the binding site to the substrate (tubulin) but not the catalytic domain, significantly decreased the endogenous TTL activity as determined in vitro [5].

Anatomical context of Ttl

• Tubulin tyrosine ligase: protein and mRNA expression in developing rat skeletal muscle [6].
• The reduction in TTL activity is not accompanied by a decrease in the tyrosination levels of microtubules, as judged by immunofluorescence analysis [5].

References