UCP2 is a mitochondrial transporter with an unusual very short half-life.

This study focused on the stability of UCP2 (uncoupling protein 2), a mitochondrial carrier located in the inner membrane of mitochondrion. UCP2 is very unstable, with a half-life close to 30 min, compared to 30 h for its homologue UCP1, a difference that may highlight different physiological functions. Heat production by UCP1 in brown adipocytes is generally a long and adaptive phenomenon, whereas control of mitochondrial ROS by UCP2 needs more subtle regulation. We show that a mutation in UCP2 shown to modify its activity, actually decreases its stability.