Critical roles of Sp1 in gene expression of human and rat H+/organic cation antiporter MATE1.
A H+/organic cation antiporter (multidrug and toxin extrusion 1: MATE1/SLC47A1) plays important roles in the tubular secretion of various clinically important cationic drugs such as cimetidine. We have recently found that the regulation of this transporter greatly affects the pharmacokinetic properties of cationic drugs in vivo. No information is available about the regulatory mechanisms for the MATE1 gene. In the present study, therefore, we examined the gene regulation of human (h) and rat (r) MATE1, focusing on basal expression. A deletion analysis suggested that the regions spanning -65/-25 and -146/-38 were essential for the basal transcriptional activity of the hMATE1 and rMATE1 promoter, respectively, and that both regions contained putative Sp1-binding sites. Functional involvement of Sp1 was confirmed by Sp1 overexpression, a mutational analysis of Sp1-binding sites, mithramycin A treatment, and an electrophoretic mobility shift assay. Furthermore, we found a single nucleotide polymorphism (SNP) in the promoter region of hMATE1 (G-32A), which belongs to a Sp1-binding site. The allelic frequency of this rSNP was 3.7%, and Sp1-binding and promoter activity were significantly decreased. This is the first study to clarify the transcriptional mechanisms of the MATE1 gene and to identify a SNP affecting the promoter activity of hMATE1.
Kajiwara
Moto
M
Department of Pharmacy, Kyoto University Hospital, Faculty of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
Terada
Tomohiro
T
Asaka
Jun-ichi
J
Ogasawara
Ken
K
Katsura
Toshiya
T
Ogawa
Osamu
O
Fukatsu
Atsushi
A
Doi
Toshio
T
Inui
Ken-ichi
K
D000818:Animals; D017920:Antiporters / Q000235:genetics*; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D002460:Cell Line; D004252:DNA Mutational Analysis; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation / Q000502:physiology*; D005787:Gene Frequency; D006801:Humans; D018374:LLC-PK1 Cells / Q000737:chemistry; D027701:Organic Cation Transport Proteins / Q000235:genetics*; D008926:Plicamycin / Q000031:analogs & derivatives / Q000494:pharmacology; D020641:Polymorphism, Single Nucleotide; D011401:Promoter Regions, Genetic; D051381:Rats; D011994:Recombinant Proteins / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000032:analysis / Q000502:physiology*; D013552:Swine; D024363:Transcription Initiation Site; D014158:Transcription, Genetic / Q000502:physiology
D017920:Antiporters; D027701:Organic Cation Transport Proteins; D011994:Recombinant Proteins; C521869:SLC47A1 protein, human; C515734:Slc47a1 protein, rat; D016329:Sp1 Transcription Factor; C066851:mithramycin A; D008926:Plicamycin