title: A role for the circadian clock protein Per1 in the regulation of the NaCl co-transporter (NCC) and the with-no-lysine kinase (WNK) cascade in mouse distal convoluted tubule cells.
abstract: It has been well established that blood pressure and renal function undergo circadian fluctuations. We have demonstrated that the circadian protein Per1 regulates multiple genes involved in sodium transport in the collecting duct of the kidney. However, the role of Per1 in other parts of the nephron has not been investigated. The distal convoluted tubule (DCT) plays a critical role in renal sodium reabsorption. Sodium is reabsorbed in this segment through the actions of the NaCl co-transporter (NCC), which is regulated by the with-no-lysine kinases (WNKs). The goal of this study was to test if Per1 regulates sodium transport in the DCT through modulation of NCC and the WNK kinases, WNK1 and WNK4. Pharmacological blockade of nuclear Per1 entry resulted in decreased mRNA expression of NCC and WNK1 but increased expression of WNK4 in the renal cortex of mice. These findings were confirmed by using Per1 siRNA and pharmacological blockade of Per1 nuclear entry in mDCT15 cells, a model of the mouse distal convoluted tubule. Transcriptional regulation was demonstrated by changes in short lived heterogeneous nuclear RNA. Chromatin immunoprecipitation experiments demonstrated interaction of Per1 and CLOCK with the promoters of NCC, WNK1, and WNK4. This interaction was modulated by blockade of Per1 nuclear entry. Importantly, NCC protein expression and NCC activity, as measured by thiazide-sensitive, chloride-dependent (22)Na uptake, were decreased upon pharmacological inhibition of Per1 nuclear entry. Taken together, these data demonstrate a role for Per1 in the transcriptional regulation of NCC, WNK1, and WNK4.
authors.affiliation: Departments of Medicine, University of Florida, Gainesville, Florida 32610; Departments of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610.
authors.forename: Jacob
authors.initials: J
authors.lastname: Richards
authors.affiliation: Department of Medicine, University of Chicago, Chicago, Illinois 60637.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Ko
authors.affiliation: Departments of Medicine, University of Florida, Gainesville, Florida 32610.
authors.forename: Sean
authors.initials: S
authors.lastname: All
authors.affiliation: Departments of Medicine, University of Florida, Gainesville, Florida 32610.
authors.forename: Kit-Yan
authors.initials: KY
authors.lastname: Cheng
authors.affiliation: Division of Nephrology, Department of Medicine, Emory University, Atlanta, Georgia 30322; Research Service, Atlanta Veterans Affairs Medical Center, Atlanta, Georgia 30033.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Hoover
authors.affiliation: Departments of Medicine, University of Florida, Gainesville, Florida 32610; Departments of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610. Electronic address: Michelle.Gumz@medicine.ufl.edu.
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Gumz
mesh_terms: D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers; D055785:Gene Knockdown Techniques; D007686:Kidney Tubules, Distal / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D056950:Period Circadian Proteins / Q000235:genetics / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D064486:Solute Carrier Family 12, Member 3 / Q000235:genetics
chemical_list: D017931:DNA Primers; C539023:Per1 protein, mouse; D056950:Period Circadian Proteins; C578875:Slc12a3 protein, mouse; D064486:Solute Carrier Family 12, Member 3; D017346:Protein Serine-Threonine Kinases
keywords: Circadian Clock; Gene Expression; Kidney; Renal Physiology; Sodium Transport; Transcription