The use of 3-fluoro-tyrosine as an alternative substrate for the enzyme tubulin:tyrosine ligase which catalyzes the incorporation of tyrosine into the α-tubulin subunit was investigated. The incorporation of tyrosine into tubulin was inhibited competitively by 3-fluoro-tyrosine with an apparent Ki of ∼ 25 μM. The affinity for this analog was similar to that of tyrosine, confirming that the hydrogen at position 3 of the aromatic ring is not essential for the reaction catalyzed by TTLase. The incorporation of 3-fluoro-tyrosine into the C-terminus of the α-turbulin subunit was demonstrated through [19F]NMR spectroscopy. The 3-fluoro-tyrosine signal at -58.6 ppm (trifluoroacetic acid as external standard), with a bandwidth of 24.7 Hz presented a chemical shift of 0.75 ppm upfield and an enlargement in the bandwidth (30.5 Hz) when incorporated into tubulin. These results strongly suggest that this amino acid is exposed to the solvent in tubulin. Tubulin covalently labeled with 3-fluoro-tyro
Microtubule-associated protein 1B (MAP1B) is the first microtubule- associated protein to be expressed during nervous system development. MAP1B belongs to a large family of proteins that contribute to the stabilization ...
Caveolin-1 (CAV1) enhanced migration, invasion, and metastasis of cancer cells is inhibited by co-expression of the glycoprotein E-cadherin. Although the two proteins form a multiprotein complex that includes beta-catenin, ...
Urra, Hery; Torres Gómez, Vicente; Ortiz, Rina J.; Lobos, Lorena; Díaz, María I.; Díaz, Natalia; Härtel, Steffen; Leyton Campos, Lisette; Quest, Andrew F. G.(PUBLIC LIBRARY SCIENCE, 2012-04-10)
Caveolin-1 is known to promote cell migration, and increased caveolin-1 expression is associated with tumor progression and metastasis. In fibroblasts, caveolin-1 polarization and phosphorylation of tyrosine-14 are essential ...