Human organic cation transporter 1 (OCT1/SLC22A1) plays important roles in the hepatic uptake of cationic drugs. The functional characteristics of this transporter have been well evaluated, but molecular information regarding transcriptional regulation is limited. In the present study, therefore, we examined the gene regulation of OCT1 gene focusing on basal core expression. An approximately 2....

Gene transcription rates and mRNA levels of plasminogen activator inhibitor type 2 (PAI-2) are markedly induced by the tumor promoting agent phorbol 12-myristate 13-acetate (PMA) in human HT1080 fibrosarcoma cells. To identify promoter elements required for basal-, and phorbol ester-inducible expression, deletion mutants of the PAI-1 promoter fused to the chloramphenicol acetyl transferase (CAT...

While the minute virus of mice (MVM) P4 promoter, which drives the viral nonstructural genes, is highly active in the absence of viral proteins, P38, the capsid gene promoter, is strictly dependent on the viral nonstructural protein NS1. Once fully transactivated, however, P38 mediates twice the steady-state level of expression achieved by P4. In this report, we address the discrepancy between ...

We have investigated the transcription factor requirements for basal expression of the mouse p53 promoter by using a combination of reporter and electrophoretic mobility shift assays (EMSAs). We have found that only four regions of the promoter bind transcription factors in EMSAs, suggesting that these are the only important factors for basal transcription. These factors are NF1, USF, ETF-like ...

Aromatase is the rate-limiting enzyme in estrogen biosynthesis and a key target in breast cancer treatment. Its ovary-specific promoter, PII, is induced in response to protein kinase A (PKA) activation. It has been proposed that breast cancer susceptibility gene 1, BRCA1, is involved in negative regulation of aromatase PII activity. Surprisingly, inhibition of PKA pathway by inhibitor H89 eleva...

The physical and functional interaction of Rnf2 (RING finger protein 2), a central component of the PRC (Polycomb repressive complex) 1 and Af9 (ALL1-fused gene from chromosome 9 protein), an aldosterone-sensitive transcription factor, in regulating basal and aldosterone-stimulated transcription of the α-ENaC (epithelial Na+ channel α-subunit) gene was explored in mIMCD3 CD (collecting duct) ce...

Microbiota of the large intestine synthesize considerable amount of vitamin B1 in the form of thiamine pyrophosphate (TPP). There is a specific high-affinity regulated carrier-mediated uptake system for TPP in human colonocytes (product of the SLC44A4 gene). The mechanisms of regulation of SLC44A4 gene expression are currently unknown. In this study, we characterized the SLC44A4 minimal promote...

Although nuclear factor (NF)-kappaB plays a central role in mediating cytokine-stimulated human inducible nitric-oxide synthase (hiNOS) gene transcription, very little is known about the factors involved in silencing of the hiNOS promoter. NF-kappaB-repressing factor (NRF) interacts with a specific negative regulatory element (NRE) to mediate transcriptional repression of certain NF-kappaB resp...

Hyperandrogenism is characteristic of women with polycystic ovary syndrome (PCOS). Ovarian theca cells isolated from PCOS follicles and maintained in long-term culture produce elevated levels of progestins and androgens compared to normal theca cells. Augmented steroid production in PCOS theca cells is associated with changes in the expression of genes for several steroidogenic enzymes, includi...