SIK2 and acute kidney injury: Catecholamines (or other renal effectors that activate PKA) may be responsible for the induction of ATF3 in the kidney during AKI by stimulating the phosphorylation and inactivation of SIK2 by PKA (as observed in white adipocytes), thereby resulting in increased transcription of AFT3 (due to a CREB/CRTC1 interaction in the kidney as occurs in white adipocytes).