Direct Analysis of Tubulin Expression in Cancer Cell Lines by Electrospray Ionization Mass Spectrometry†

ABSTRACT: Differential expression of tubulin isotypes, mutations, and/or post-translational modifications in sensitive and Taxol-resistant cell lines suggests the existence of tubulin-based mechanisms of resistance. Since tubulin isotypes are defined by their C-terminal sequence, we previously described a matrix-assisted laser desorption/ionization time-of-flight mass spectrometry-based analysis of tubulin diversity in human cell lines by analysis of their CNBr-released C-terminal peptides [Rao, S., Aberg, F., Nieves, E., Horwitz