EGFP Fused to the Microtubule-Associated Protein TPX2
Enhanced green fluorescent protein (EGFP) was mutated from the GFPS65T variant of Aequorea victoria-derived wtGFP by replacing the amino acid phenylalanine for leucine at position 64. The result was a relatively bright and photostable fluorescent protein with improved maturation efficiency and an excitation spectral profile that makes it well suited for use with the 488-nanometer argon ion laser line. The localization of EGFP fused to TPX2, a targeting protein involved in the binding of the C-terminal domain of Xenopus kinesin-like protein (Xklp2) to microtubules, is demonstrated in the digital image above. TPX2 is phosphorylated during the process of mitosis.