Format

Send to

Choose Destination
Biochim Biophys Acta. 2001 Sep 21;1520(3):234-41.

Promoter characterization and genomic organization of the human breast cancer resistance protein (ATP-binding cassette transporter G2) gene.

Author information

1
Department of Pathology, University of Maryland School of Medicine, Baltimore, MD 21205, USA.

Abstract

The breast cancer resistance protein (BCRP) gene, formally known as ATP-binding cassette transporter G2 (ABCG2) gene, encodes an ABC half transporter that causes resistance to certain cancer chemotherapeutic drugs when transfected and expressed in drug sensitive cancer cells. Here we report the organization of the BCRP gene, and the initial characterization of the BCRP promoter. We identified the genomic sequence of BCRP and its promoter by screening a human genomic lambda phage library, as well as a BAC library, and by searching the human genome database. The BCRP gene spans over 66 kb and consists of 16 exons and 15 introns. The exons range in size from 60 to 532 bp. The translational start site is found in the second exon. The first exon contains the majority of the 5' UTR. Promoter activity was characterized by a luciferase reporter assay using transient transfection of the human breast cancer cell line MCF7, and the human choriocarcinoma cell lines JAR, BeWo and JEG-3, which we find to have high endogenous expression of BCRP. The BCRP gene is transcribed by a TATA-less promoter with several putative Sp1 sites, which are downstream from a putative CpG island. The sequence 312 bp directly upstream from the BCRP transcriptional start site conferred basal promoter activity. The 5' region upstream of the basal promoter is characterized by both positive and negative regulatory domains.

PMID:
11566359
DOI:
10.1016/s0167-4781(01)00270-6
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center