RT Journal Article
SR Electronic
T1 Differential Selection of Acridine Resistance Mutations in Human DNA Topoisomerase IIβ Is Dependent on the Acridine Structure
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 1006
OP 1014
DO 10.1124/mol.106.032953
VO 71
IS 4
A1 Chrysoula Leontiou
A1 Gary P. Watters
A1 Kathryn L. Gilroy
A1 Pauline Heslop
A1 Ian G. Cowell
A1 Kate Craig
A1 Robert N. Lightowlers
A1 Jeremy H. Lakey
A1 Caroline A. Austin
YR 2007
UL http://molpharm.aspetjournals.org/content/71/4/1006.abstract
AB Type II DNA topoisomerases are targets of acridine drugs. Nine mutations conferring resistance to acridines were obtained by forced molecular evolution, using methyl N-(4′-(9-acridinylamino)-3-methoxy-phenyl) methane sulfonamide (mAMSA), methyl N-(4′-(9-acridinylamino)-2-methoxy-phenyl) carbamate hydrochloride (mAMCA), methyl N-(4′-(9-acridinylamino)-phenyl) carbamate hydrochloride (AMCA), and N-[2-(dimethylamino)ethyl]acridines-4-carboxamide (DACA) as selection agents. Mutations βH514Y, βE522K, βG550R, βA596T, βY606C, βR651C, and βD661N were in the B′ domain, and βG465D and βP732L were not. With AMCA, four mutations were selected (βE522K, βG550R, βA596T, and βD661N). Two mutations were selected with mAMCA (βY606C and βR651C) and two with mAMSA (βG465D and βP732L). It is interesting that there was no overlap between mutation selection with AMCA and mAMSA or mAMCA. AMCA lacks the methoxy substituent present in mAMCA and mAMSA, suggesting that this motif determines the mutations selected. With the fourth acridine DACA, five mutations were selected for resistance (βG465D, βH514Y, βG550R, βA596T, and βD661N). βG465D was selected with both DACA and mAMSA, and βG550R, βA596T, and βD661N were selected with both DACA and AMCA. DACA lacks the anilino motif of the other three drugs but retains the acridine ring motif. The overlap in selection with DACA and mAMSA or AMCA suggests that altered recognition of the acridine moiety may be involved in these mutations. We used restriction fragment length polymorphisms and heteroduplex analysis to demonstrate that some mutations were selected multiple times (βG465D, βE522K, βG550R, βA596T, and βD661N), whereas others were selected only once (βH514Y, βY606C, βR651C, and βP732L). Here, we compare the drug resistance profile of all nine mutations and report the biochemical characterization of three, βG550R, βY606C, and βD661N. The American Society for Pharmacology and Experimental Therapeutics