Functional analysis of SNPs variants of BCRP/ABCG2
Functional analysis of SNPs variants of BCRP/ABCG2
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DOI：
10.1023/b:pham.0000045245.21637.d4
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发表时间：
2004-10-01
影响因子：
3.7
通讯作者：
Sugiyama, Y
中科院分区：
文献类型：
--
作者：
Kondo, C;Suzuki, H;Sugiyama, Y
目的.本研究旨在探讨乳腺癌耐药蛋白（BCRP/ABCG 2）单核苷酸多态性（SNPs）对其定位、表达水平和转运活性的影响。在将质粒载体中的cDNA转染至LLC-PK 1细胞后，使用BCRP的野生型和7种不同SNP变体（V12 M、Q141 K、A149 P、R163 K、Q166 E、P269 S和S441 N BCRP）鉴定细胞定位。用重组腺病毒感染HEK 293细胞，检测其表达水平和转运活性。野生型和六种不同的SNP变体BCRP的S441 N BCRP以外的顶膜上表达，而S441 N BCRP显示细胞内定位。Q141 K和S441 N BCRP蛋白的表达水平显著低于野生型和其他5种变体。此外，野生型、V12 M、Q141 K、A149 P、R163 K、Q166 E和P269 S BCRP的E1 S、DHEAS、MTX和PAH的转运活性（通过BCRP蛋白表达水平标准化）几乎相同。这些结果表明，Q141 K SNPs可能与较低的表达水平相关，S441 N SNPs可能影响表达水平和细胞定位。具有这些多态性的受试者可能具有较低的BCRP蛋白表达水平，因此输出这些底物的能力降低。
Purpose. The aim of the current study was to identify the effect of single nucleotide polymorphisms ( SNPs) in breast cancer resistance protein (BCRP/ABCG2) on its localization, expression level, and transport activity.Methods. The cellular localization was identified using the wild type and seven different SNP variants of BCRP (V12M, Q141K, A149P, R163K, Q166E, P269S, and S441N BCRP) after transfection of their cDNAs in plasmid vector to LLC-PK1 cells. Their expression levels and transport activities were determined using the membrane vesicles from HEK293 cells infected with the recombinant adenoviruses containing these kinds of BCRP cDNAs.Results. Wild type and six different SNP variants of BCRP other than S441N BCRP were expressed on the apical membrane, whereas S441N BCRP showed intracellular localization. The expression levels of Q141K and S441N BCRP proteins were significantly lower compared with the wild type and the other five variants. Furthermore, the transport activity of E1S, DHEAS, MTX, and PAH normalized by the expression level of BCRP protein was almost the same for the wild type, V12M, Q141K, A149P, R163K, Q166E, and P269S BCRP.Conclusions. These results suggest that Q141K SNPs may associate with a lower expression level, and S441N SNPs may affect both the expression level and cellular localization. It is possible that subjects with these polymorphisms may have lower expression level of BCRP protein and, consequently, a reduced ability to export these substrates.