Biomedical subjects

R Wooster

Publications and source records attributed to R Wooster.

40 records · Page 3Linked to original sources

PubMed1991

Investigation of the molecular basis of the genetic deficiency of UDP-glucuronosyltransferase in Crigler-Najjar syndrome.

Liver biopsy samples were obtained from eight Crigler-Najjar patients. Bilirubin UDPGT activity, assayed by a microassay with HPLC analysis, was not detectable in type I livers, and low levels (9-26% of controls) of monoglucuronide conjugates only were observed in type II livers. 1-Naphthol UDPGT activity was normal in most patients, where membrane integrity was maintained by correct sample procurement and preparation. Our data on type II livers suggest that a defect in UDPGA transport is an unlikely cause of the hyperbilirubinaemia, but reduced affinity for UDPGA was observed in one sample. Analysis of four patient liver samples by immunoblot analysis revealed the heterogeneous nature of this inherited disease within the patient population, and one sample where 1-naphthol UDPGT activity was considerably reduced appeared to correlate with the non-detection of a phenol UDPGT protein. Progress towards a molecular genetic diagnosis of Crigler-Najjar syndromes is discussed.

Aged↗

PubMed1990

Characterization and primary sequence of a human hepatic microsomal estriol UDPglucuronosyltransferase.

A human liver microsomal UDP glucuronosyltransferase (UDPGT) that demonstrates reactivity with estriol (pI 7.4 UDPGT) has been purified to homogeneity and characterized further. No activity toward morphine, 4-hydroxybiphenyl, bilirubin, or tripelennamine was observed. The estriol UDPGT shows immunoreactivity with antibodies raised against rat hepatic microsomal 3 alpha- and 17 beta-hydroxysteroid UDPGTs but not with antibodies raised against rat hepatic microsomal p-nitrophenol UDPGT. The NH2-terminal sequence of the purified protein was determined and found to correspond to an identical sequence in the deduced amino acid sequence of a cDNA obtained from a human liver library in lambda gt11 (HLUG4). Sequence analysis revealed that HLUG4 is 2094 bp in length and encodes a protein of 523 amino acids which has a 16 amino acid leader sequence, followed by an untranslated 3' region of 525 bp. Three potential N-glycosylation sites were identified in the predicted sequence. The deduced amino acid sequence of estriol UDPGT showed 82% identity with the deduced amino acid sequence of another human hepatic cDNA (HLUG25), which has been expressed as a UDPGT capable of 6 alpha-hydroxyglucuronidation of hyodeoxycholic acid, strongly suggesting that these proteins are members of the same gene subfamily.

Amino Acid Sequence↗

PubMed1989

Expression of a human liver cDNA encoding a UDP-glucuronosyltransferase catalysing the glucuronidation of hyodeoxycholic acid in cell culture.

A cDNA encoding a human liver UDPGT (HLUG 25) transcribed and translated in vitro showed that the encoded protein was synthesized as a precursor and was cleaved and glycosylated when dog pancreatic microsomes were present during translation. The UDPGT cDNA was transiently expressed in mammalian cell culture (COS-7 cells) resulting in the biosynthesis of a polypeptide of 52 kDa. This expressed UDPGT glycoprotein catalysed the glucuronidation of hyodeoxycholic acid forming an ether glucuronide. These results suggest that this UDPGT isoenzyme may be responsible for the glucuronidation of 6 alpha-hydroxy bile acids in human liver.

Animals↗

PubMedDate not supplied

Identification of the breast cancer susceptibility gene BRCA2.

In Western Europe and the United States approximately 1 in 12 women develop breast cancer. A small proportion of breast cancer cases, in particular those arising at a young age, are attributable to a highly penetrant, autosomal dominant predisposition to the disease. The breast cancer susceptibility gene, BRCA2, was recently localized to chromosome 13q12-q13. Here we report the identification of a gene in which we have detected six different germline mutations in breast cancer families that are likely to be due to BRCA2. Each mutation causes serious disruption to the open reading frame of the transcriptional unit. The results indicate that this is the BRCA2 gene.

Amino Acid Sequence↗