Fig. 1.

The nuclear location of HO-1

Under scores of stress stimuli, heme oxygenase-1 initiates certain protein cleavage mechanisms in cells, hydrolyzes, and removes the carboxy-terminal amino acid sequence to form a truncated protein form. The truncated HO-1 dissociates in the cytoplasm and then is transported into the cell under some vital mechanisms. What follows next, nuclear HO-1 responds to the initial emergency stimulus by regulating the expression level of the target gene. That contains a variety of potential new regulatory mechanisms.