background:
In human liver cytosolic fractions, four forms of biliverdin reductase have been identified, including two biliverdin-IX Beta reductases and two biliverdin-IX Alpha reductases, designated isozymes I and II and isozymes III and IV, respectively. Biliverdin reductase A (BLVRA), also designated biliverdin-IX Alpha-reductase, belongs to the GFO/iIDH/MocA family and the biliverdin reductase subfamily. The gene that encodes this cytoplasmic protein maps to chromosome 7p14-cen. BLVRA reduces biliverdin IX ?(the ?methene bridge of the open tetrapyrrole) to bilirubin with the concomitant oxidation of an NADH or NADPH cofactor (bilirubin + NADP+ = biliverdin + NADPH). BLVRA is expressed primarily in liver.
Function:
Biliverdin Reductase (BVR) catalyzes the final step in the heme metabolic pathway, the reduction of biliverdin IX{alpha} to bilirubin, with the concomitant oxidation of a NADH or NADPH cofactor. The enzyme remains unique among all biological catalysts described to date in having a dual pH/cofactor-dependent activity profile. Human biliverdin reductase (hBVR) has been recently shown to be a Ser/Thr/Tyr kinase in the MAPK insulin/insulin-like growth factor 1 (IGF1)-signaling cascade. BVR together with its substrate, biliverdin, and product, bilirubin, have recently been revealed to be important players in cellular signal transduction pathways, gene expression and oxidative response. These features make BVR unusually interesting and unique among all enzymes characterized to date.
Subunit:
Monomer.
Subcellular Location:
Cytoplasmic
Tissue Specificity:
Liver.
DISEASE:
Defects in BLVRA are the cause of hyperbiliverdinemia(HBLVD) [MIM:614156]. HBLVD is a condition characterized by a greendiscoloration of the skin, urine, serum, and other bodily fluids.It is due to increased biliverdin resulting from inefficientconversion to bilirubin. Affected individuals appear to havesymptoms only in the context of obstructive cholestasis and/orliver failure. In some cases, green jaundice can resolve afterresolution of obstructive cholestasis.
Similarity:
Belongs to the Gfo/Idh/MocA family. Biliverdinreductase subfamily.
Database links:
Entrez Gene: 644 Human
Entrez Gene: 109778 Mouse
Entrez Gene: 116599 Rat
Omim: 109750 Human
SwissProt: P53004 Human
SwissProt: Q9CY64 Mouse
SwissProt: P46844 Rat
Unigene: 488143 Human
Important Note:
This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications.
|
|
