Characterization of a kidney-specific pattern of chromatin structure in the rat phosphoenolpyruvate carboxykinase gene.
The kidney-specific chromatin structure of the phosphoenolpyruvate carboxykinase (PEPCK) gene was examined and compared to that of the liver. Kidney nuclear extracts were found to lack a liver-enriched factor, pepA, that binds to HSS A, a distal enhancer of the PEPCK gene that may be involved in opening the chromatin domain of the PEPCK gene in the liver. To begin the characterization of the kidney-specific chromatin structure of the PEPCK gene, nuclease hypersensitive sites (HSS) were mapped by indirect end-labeling analysis in proximal tubules from control rats, proximal tubules from acidotic rats which express induced levels of PEPCK, and NRK52E cells, a rat kidney epithelial cell line which does not express the PEPCK gene. A subset of HSS, at -400/+1 over the proximal promoter and at +1900 within the coding region, correlate with kidney-specific PEPCK expression. Two other HSS, at -3.1 kb and +6.2 kb, are detected in kidney cells regardless of PEPCK expression. The HSS at -4800, -1240, and +4650, previously identified in PEPCK-expressing liver cells, were not observed in the kidney. As in the liver, the pattern of hypersensitivity in the kidney does not change by altering the rate of transcription.
Cissell
M A
MA
Department of Molecular Physiology and Biophysics, Vanderbilt University, 741 Light Hall, Nashville, TN 37232, USA.
Chalkley
R
R
D000138:Acidosis / Q000201:enzymology; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D002843:Chromatin / Q000737:chemistry*; D003850:Deoxyribonuclease I; D007668:Kidney / Q000737:chemistry* / Q000201:enzymology / Q000648:ultrastructure; D007687:Kidney Tubules, Proximal / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D008099:Liver / Q000737:chemistry / Q000201:enzymology; D008297:Male; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000096:biosynthesis / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley
D002843:Chromatin; D003850:Deoxyribonuclease I; D010729:Phosphoenolpyruvate Carboxykinase (GTP)