Frontiers in Pharmacology (Mar 2012)
Biliverdin reductase: more than a namesakeThe reductase, its peptide fragments and biliverdin regulate activity of the three classes of protein kinase C.
Abstract
The expanse of human biliverdin reductase (hBVR) functions in the cells is arguably umatched by any single protein. hBVR is a Ser/Thr/Tyr kinase, a scaffold protein, a transcription factor and an intracellular transporter of gene regulators. hBVR is an upstream activator of the insulin/IGF-1 signaling pathway and of PKC kinases in the two major arms of the pathway. In addition, it is the sole means for generating the antioxidant bilirubin-IXα. hBVR is essential for activation of ERK1/2 kinases by upstream MAPKK-MEK and by PKCδ, as well as the nuclear import and export of ERK1/2. Small fragments of hBVR are potent activators and inhibitors of the ERK kinases and PKCs: as such, they suggest the potential application of BVR-based technology in therapeutic settings. Presently, we have reviewed the function of hBVR in cell signaling with an emphasis on regulation of PKCδ activity.
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