TY - JOUR
T1 - Functional effects of single nucleotide polymorphisms in the coding region of human N-acetyltransferase 1
AU - Zhu, Y.
AU - Hein, D. W.
N1 - Funding Information:
We thank Dr Edith Sim, Oxford University, UK for her generous donation of human NAT1 antibody. This work was partially supported by United States Public Health Service grant CA-34627 from the National Cancer Institute, and a grant from the Kentucky Lung Cancer Research Program. Portions of the work constituted partial fulfillment of the PhD in pharmacology and toxicology awarded to Yuanqi Zhu at the University of Louisville.
PY - 2008
Y1 - 2008
N2 - Genetic variants of human N-acetyltransferase 1 (NAT1) are associated with cancer and birth defects. N- and O-acetyltransferase catalytic activities, Michaelis-Menten kinetic constants (Km and Vmax) and steady-state expression levels of NAT1-specific mRNA and protein were determined for the reference NAT1*4 and variant human NAT1 haplotypes possessing single nucleotide polymorphisms (SNPs) in the open reading frame. Although none of the SNPs caused a significant effect on steady-state levels of NAT1-specific mRNA, C97T(R33stop), C190T(R64W), C559T (R187stop) and A752T(D251V) each reduced NAT1 protein level and/or N- and O-acetyltransferase catalytic activities to levels below detection. G560A(R187Q) substantially reduced NAT1 protein level and catalytic activities and increased substrate Km. The G445A(V149I), G459A(synonymous) and T640G(S214A) haplotype present in NAT1*11 significantly (P<0.05) increased NAT1 protein level and catalytic activity. Neither T21G(synonymous), T402C(synonymous), A613G(M205V), T777C(synonymous), G781A(E261K) nor A787G(I263V) significantly affected Km, catalytic activity, mRNA or protein level. These results suggest heterogeneity among slow NAT1 acetylator phenotypes.
AB - Genetic variants of human N-acetyltransferase 1 (NAT1) are associated with cancer and birth defects. N- and O-acetyltransferase catalytic activities, Michaelis-Menten kinetic constants (Km and Vmax) and steady-state expression levels of NAT1-specific mRNA and protein were determined for the reference NAT1*4 and variant human NAT1 haplotypes possessing single nucleotide polymorphisms (SNPs) in the open reading frame. Although none of the SNPs caused a significant effect on steady-state levels of NAT1-specific mRNA, C97T(R33stop), C190T(R64W), C559T (R187stop) and A752T(D251V) each reduced NAT1 protein level and/or N- and O-acetyltransferase catalytic activities to levels below detection. G560A(R187Q) substantially reduced NAT1 protein level and catalytic activities and increased substrate Km. The G445A(V149I), G459A(synonymous) and T640G(S214A) haplotype present in NAT1*11 significantly (P<0.05) increased NAT1 protein level and catalytic activity. Neither T21G(synonymous), T402C(synonymous), A613G(M205V), T777C(synonymous), G781A(E261K) nor A787G(I263V) significantly affected Km, catalytic activity, mRNA or protein level. These results suggest heterogeneity among slow NAT1 acetylator phenotypes.
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U2 - 10.1038/sj.tpj.6500483
DO - 10.1038/sj.tpj.6500483
M3 - Article
C2 - 17909564
AN - SCOPUS:52749085010
SN - 1470-269X
VL - 8
SP - 339
EP - 348
JO - Pharmacogenomics Journal
JF - Pharmacogenomics Journal
IS - 5
ER -