EXPRESSION OF SPECIFIC PROTEIN KINASE C (PKC) ISOFORMS AND LIGAND-SPECIFIC ACTIVATION OF PKCα IN LATE GESTATION FETAL LUNG

Abstract

Epidermal growth factor receptor signaling plays an important role in lung maturation. The authors hypothesized that specific protein kinase C (PKC) isoforms are expressed and activated by epidermal growth factor (EGF) and transforming growth factor α (TGFα) (EGF receptor [EGFR] ligands) in fetal lung fibroblasts. The authors found 4 PKC isoforms expressed in gestational day 19 (d19) fetal rat lung fibroblasts, and focused on PKCα because of its developmental expression pattern. PKCα immunolocalization in d17, d19, and d21 fetal lung fibroblasts was similar to EGFR. PKCα expression decreased with lung maturation. EGF, but not TGFα, stimulated PKCα activation and membrane translocation. Further studies of PKCα functions in fetal lung development are clearly needed.

Keywords:

• EGF receptor (EGFR)
• epidermal growth factor (EGF)
• signal transduction
• transforming growth factor α (TGFα)