Figure 7.

Pax8-dependent osmoregulation of Slc14a2. (A) Protein lysates from IMCD cells cultured with 500 mM NaCl were isolated at various times after salt addition and blotted for Pax8 and Pax2. (B) Expression of UTs was measured post salt addition. (C) As in (B), AQP mRNAs were measured in response to high-salt addition in IMCD cells. (D) A schematic of exons 1 and 2 of the Slc14a2 gene on mouse chromosome 18 is shown with the position of primer pairs used for ChIP indicated. (E and F) IMCD cells cultured under 300 or 500 mM NaCl show increase in Pax8 protein and increased UTA1 and UTA3 expression (*P<0.01). (G–M) ChIP experiments using chromatin form IMCD cells cultured with 300 or 500 mM NaCl and immunoprecipitated with the indicated antibodies. Note binding of Pax8 near primer pairs 4 and 6, the recruitment of PTIP, Ash2L, and Rbbp5, and the increase in H3K4me2 and RNA Pol II. ChIP PCR reactions were run in triplicate for two independent chromatin sets. Error bars are one SD from the mean.