G-protein receptor kinases 2, 5 and 6 redundantly modulate Smoothened-GATA transcriptional crosstalk in fetal mouse hearts

Schematic depiction showing how GRK regulates Hh/Smo-GATA transcriptional crosstalk. (A) In the presence of GRK, Hedgehog family members (Hh; orange) bind to Ptc (Patched: rust), releasing and activing Smo (blue) that, via Gi- and GRK-transduced signals, relieves Fused (Fu) and Suppressor of Fused (SuFu) proteins (light green) that sequester the transcription factor Gli (forsest green) in the cytoplasm, thus permitting it to translocate to the nucleus where it stimulates Hh- and GATA-dependent gene expression. (B) In absence of GRK. Hh bind to Ptc thus activing Smo, but the absence of GRK suppressed Smo-stimulation of the transcription factor Gli, that is now not able to migrate into the nucleus to promote GATA-and Hh-dependent transcriptions.111