Fig. 5. (A) Inhibition of P-p38 with SB203580 prevents phosphorylation of ATF2 and up-regulation of ATF3. Confluent HK monolayers were either untreated to serve as a control, or pretreated with SB203580 for 1 hour. Scrape wounds were generated and allowed to incubate for 2.5 hours in the presence or absence of inhibitor. ATF2 phosphorylation (P-ATF-2; a,b) and ATF3 (c,d) protein expression levels were examined by immunofluorescent staining. SB203580 blocked expression of P-ATF-2 and ATF-3. (B) Pretreatment of scrape wounds with the membrane-permeable form of the JNK peptide inhibitor (JNK Peptide Inhibitor 1, L stereoisomer; 50 µM, 30 minutes prior to wounding) (Bonny et al., 2001) prevents phosphorylation of jun but not expression of ATF3. Bar, 25 µm.