Table 2.

Hot spots correlating between β-tubulin isotype sequences and β-tubulin mutations associated with acquired drug resistance. All residues identified as being nonconserved among the Human β-Tubulin isotypes were compared with those identified in Table 1. The isotypes in which the change occurs are identified with the differing residues in parentheses.

Residue	Mutant	Mutant Phenotype	β-tubulin Isotype Expression
45	D45Y	CN resistant	βI(D) βII–VIII(E)
172	S172A	CN resistant	βI–VI,VIII(S) βVII(L)β
231	A231T	PTX resistant	βI–V,VII,VIII(A) βVI(L)
364	A364T	PTX resistant	βI,VII(V) βIII,V(S) βII,IV,VI,VIII(A)