Isolation and characterization of cloned cDNAs encoding human liver chlordecone reductase

Abstract

Chlordecone (Kepone), a toxic organochlorine pesticide, undergoes bioreduction to chlordecone alcohol in human liver. This reaction is controlled by a cytosolic enzyme, chlordecone reductase (CDR), which may be of the aldo-keto reductase family of xenobiotic metabolizing enzymes [Molowa et al. (1986) J. Biol. Chem. 261, 12624-12627]. To further investigate the primary structure and expression of CDR, we screened a library of human liver cDNAs cloned in the expression vector lambda gt11 and isolated an 800 bp cDNA that directed synthesis of a fusion protein recognized by polyclonal anti-CDR antibodies. Using this cDNA as a probe, we screened two human liver cDNA libraries and found several 1.2-kb cDNAs which would code for a polypeptide with 308 residues (35.8 kDa). However, a similar full-length cDNA, possibly the transcript of a pseudogene, contained an in-frame nonsense codon. The deduced protein sequence of CDR showed 65% similarity to the primary structure of human liver aldehyde reductase and 66% similarity to the inferred protein sequence of rat lens aldose reductase. A search of GenBank revealed significant nucleotide similarity to a cDNA coding for bovine lung prostaglandin f synthase and to a partial cDNA coding for frog lens rho-crystallin. Southern blot analysis of human genomic DNA displayed between 45 and 65 kilobases of DNA hybridizable to CDR cDNA and demonstrated several restriction fragment length polymorphisms among 26 individuals. Northern blot analysis of RNA from human, gerbil, rabbit, hamster, mouse, and rat livers disclosed hybridization with CDR cDNA only for the first three species.(ABSTRACT TRUNCATED AT 250 WORDS)

Close kinship of human 20α‐hydroxysteroid dehydrogenase gene with three aldo‐keto reductase genes

“…In the present study, cDNAs encoding 20a-HSD, BABP and DD4 were cloned. Sequences encoding these 20a-HSD, BABP, PGFS and DD4 cDNAs completely matched our exon sequences, as well as those of reported cDNA sequences (Winters et al 1990;Qin et al 1993;Hara et al 1996;SuzukiYamamoto et al 1999) at an amino acid level, and almost identical at a nucleotide level except for a few silent base changes. Then, 20a-HSD, BABP and DD4 were expressed in bacteria and subjected to kinetic analysis in the presence of the cofactor NADPH or NADP to compare substrate speci®city.…”

An ethoxyquin-inducible aldehyde reductase from rat liver that metabolizes aflatoxin B1 defines a subfamily of aldo-keto reductases.

“…AUXil5, an open-reading frame in an auxin-induced mRNA from Nicotiana tabacum (15) (19), a member of the aldo-keto reductase family (20). Comparisons between AFB1-AR and human placental aldose reductase (20), another member of the aldo-keto reductase family, revealed 20% identity (43% similarity) ( Table 2).…”

“…These regions of similarity cover areas of the aldose reductase protein that are thought to be involved in cofactor binding (21,22). (17); BBOAKR, putative aldo-keto reductase from B. bovis (18); CHLDR, human chlordecone reductase (19); ALDR, human placental aldose reductase (20); n, residues ofALDR thought to be involved in cofactor binding (21,22); d, potential hydrogen donor sites of ALDR (21,22); *, residues of AFB1-AR that are identical to cofactor binding or potential hydrogen donor sites ofALDR. Shaded residues indicate identity between all sequences (allowing for one mismatch).…”

“…Comparison of the deduced amino acid sequence of AFB1-AR with those of members of the aldo-keto reductase superfamily indicates that it is most closely related (24% identity) to chlordecone reductase, a human liver enzyme involved in the detoxification of the organochlorine pesticide chlordecone (19). By contrast, other members of the aldo-keto reductase superfamily possess between 45% and 70% identity with each other (20); these enzymes catalyze the reduction of aldehyde and ketone groups on a wide variety of substrates including sugars (20), steroid hormones (42,43), and toxic aldehydes (44), as well as the oxidation of trans-dihydrodiols of polycyclic aromatic hydrocarbons and steroid hormones (43,45).…”

Amino Acid Sequence and Characterization of Aldo-keto Reductase from Bakers’ Yeast

“…It is noted that the substrate specificity of yeast aldo-keto reductase is similar to that of aldehyde reductase from Sporobolomyces sa/monic%r. 20) Yeast aldo-keto reductase requires NADPH as the coenzyme, and similarly to other aido-keto reductases, NADH-dependent reduction, or NAD + -and NADP+ -dependent oxidations of typical alcohols such as ethanol and ex-and O-hydroxy esters are undetectable. 12) Typical ex-and fJ-keto esters are reduced by yeast aido-keto reductase.…”