Multidrug resistance protein-2 encoded by the ABCC2 gene (MRP2/ABCC2), an efflux transporter expressed at the proximal renal tubule, is rate-limiting for urine excretion of coproporphyrin (UCP) isomers I and III, translating in high UCP [I/(I + III)] ratio in MRP2-deficient patients presenting with the Dubin-Johnson Syndrome.
The molecular basis in Dubin-Johnson syndrome is absence or deficiency of human canalicular multispecific organic anion transporter MRP2/cMOAT caused by homozygous or compound heterozygous mutation(s) in ABCC2 located on chromosome 10q24.
FVII deficiency in both populations is caused by a founder A244V mutation in the F7 gene and DJS is caused by two founder mutations, I1173F and R1150H in the MRP2 gene that are specific for Iranian and Moroccan Jewish patients, respectively.
Several naturally occurring mutations leading to the absence of functional MRP2 protein from the apical membrane have been described causing the human Dubin-Johnson syndrome associated with conjugated hyperbilirubinaemia.
In the present study, we report the effects of chronic administration of both drugs in a patient with Dubin-Johnson syndrome (DJS), an inherited autosomal recessive disorder characterized by the absence of functional MRP2 protein at the canalicular hepatocyte membrane.
To clarify the genetic basis of the disease and the long-term stability of serum bilirubin levels, we conducted a mutational analysis of the MRP2 gene and followed up serum bilirubin levels in Japanese DJS patients 30 years after they were originally diagnosed, based on traditional criteria.
Dubin-Johnson syndrome (DJS) is an autosomal recessive disorder characterized by conjugated hyperbilirubinemia and caused by mutations of the ATP-binding cassette (ABC) transporter encoding gene MRP2/cMOAT/ABCC2.
In this work, we analyzed a relatively frequent Dubin-Johnson syndrome mutation that leads to an exchange of two hydrophobic amino acids, isoleucine 1173 to phenylalanine (MRP2I1173F), in a predicted extracellular loop of MRP2.
We investigated the consequences of 2 missense mutations, R768W and Q1382R, of nucleotide-binding domains (NBDs) of the multidrug resistance protein 2 (MRP2; ABCC2) that were previously identified in patients with DJS.
The aim of this study was to identify the mutations in two previously characterized clusters of patients with Dubin-Johnson syndrome among Iranian and Moroccan Jews and determine the consequence of the mutations on MRP2 expression and function by expression studies.
Several mutations in the human MRP2 gene have been identified that lead to the absence of MRP2 from the canalicular membrane and to the conjugated hyperbilirubinemia of Dubin-Johnson syndrome.
This is the first mutation in Dubin-Johnson syndrome shown to cause deficient MRP2 maturation and impaired sorting of this glycoprotein to the apical membrane.
Several mutations in the human MRP2 gene have been identified which lead to the absence of the MRP2 protein from the hepatocyte canalicular membrane and to the conjugated hyperbilirubinemia of Dubin-Johnson syndrome.
We previously isolated a canalicular multispecific organic anion transporter, cMOAT1/MRP2, that belongs to the ATP binding cassette (ABC) superfamily, which is specifically expressed in liver, and cMOAT1/MRP2 is responsible for the defects in hyperbilirubinemia II/Dubin-Johnson syndrome.