Housekeeping Na,K-ATPase α1 Subunit Gene Promoter Is Composed of Multiple cis Elements to Which Common and Cell Type-Specific Factors Bind

Abstract

Na,K-ATPase alpha 1 subunit gene (ATP1A1) is one of the housekeeping genes involved in homeostasis of Na+ and K+ in all animal cells. We identified and characterized the cis-acting elements that regulate the expression of ATP1A1. The region between -155 and -49 was determined as a positive regulatory region in five cultured cell lines of different tissue origins (MDCK, B103, L6, 3Y1, and HepG2). The region was divided into three subregions: from -120 to -106 (including the Sp1 binding site), from -102 to -61, and from -58 to -49 (including an Sp1 consensus sequence). Cell type-specific factors binding to the middle subregion (from -102 to -61) were detected by gel retardation analysis, using nuclear extracts prepared from MDCK and B103 cells. Two gel retardation complexes were formed in the B103 nuclear extract, and three were formed in the MDCK nuclear extract. DNA binding regions of these factors were located at -88 to -69 and differed from each other in DNase I footprinting experiments. These factors also showed different binding characteristics in gel retardation competition and methylation interference experiments. The identified cis element was named the ATP1A1 regulatory element. The core sequence of this element is found in several other genes involved in cellular energy metabolism, suggesting that the sequence is a common regulatory element responsive to the state of energy metabolism.

Effect of Intestinal Flora on Protein Expression of Drug-Metabolizing Enzymes and Transporters in the Liver and Kidney of Germ-Free and Antibiotics-Treated Mice

“…Gapdh for the cytosolic fraction and Na + /K + -ATPase for crude and plasma membrane fractions were also quantitated as housekeeping proteins, 35,36 and their changes ranged from 0.788-fold to 1.53-fold in GF and VCM+PLB mice (Figure 2A and B). The expression levels of Na + /K + -ATPase in crude and plasma membrane fractions of model mice were not significantly different from those in the controls.…”

Time-course recovery of estrogen-responsive genes of a cichlid fish exposed to waterborne octylphenol

“…In this experimental design, we were able to detect marked changes in estrogen-responsive genes and plasma proteins, and also in liver histology of C. dimerus males after exposure to150 g/L OP during 28 days. Among these estrogen-responsive genes, we choose Na + /K + -ATPase since it is a ubiquitous enzyme involved in homeostasis in metazoan cells (Suzuki-Yagawa et al, 1992). The Na + /K + -ATPase provides the driving forces for the control of the ionic environment in the cytosol, cell volume, intracellular pH, and transport of nutrients and metabolites.…”

DNA-Binding and Regulation Mechanisms of the SIX Family of Retinal Determination Proteins

“…The regulatory targets of some Six proteins are known, and Six DNA-binding sites have been identified using DNA footprinting and related techniques. Six4 , Six2, and Six5 bind to the “ARE” regulatory element of the Na + /K + ATPase α1 subunit gene, GGTG TCAGGTT GC. The closely related MEF3 motif, TCAGGTT (underlined in the ARE motif), present in the myogenin promoter is also recognized by Six1 and Six4 .…”