Identification and characterization of zebrafish SULT1 ST9, SULT3 ST4, and SULT3 ST5.

By searching the GenBank database, we identified sequences encoding three new zebrafish cytosolic sulfotransferases (SULTs). These three new zebrafish SULTs, designated SULT1 ST9, SULT3 ST4, and SULT3 ST5, were cloned, expressed, purified, and characterized. SULT1 ST9 appeared to be mostly involved in the metabolism and detoxification of xenobiotics such as β-naphthol, β-naphthylamine, caffeic acid and gallic acid.

Archaea signal recognition particle shows the way.

Archaea SRP is composed of an SRP RNA molecule and two bound proteins named SRP19 and SRP54. Regulated by the binding and hydrolysis of guanosine triphosphates, the RNA-bound SRP54 protein transiently associates not only with the hydrophobic signal sequence as it emerges from the ribosomal exit tunnel, but also interacts with the membrane-associated SRP receptor (FtsY). Comparative analyses of the archaea genomes and their SRP component sequences, combined with structural and biochemical data, support a prominent role of the SRP RNA in the assembly and function of the archaea SRP.

Zebrafish as a model for the study of the phase II cytosolic sulfotransferases.

Cytosolic sulfotransferases (SULTs) are traditionally known as the Phase II drug-metabolizing or detoxifying enzymes that serve for the detoxification of drugs and other xenobiotics. These enzymes in general catalyze the transfer of a sulfonate group from the active sulfate, 3'-phosphoadenosine 5'-phosphosulfate (PAPS), to low-molecular weight substrate compounds containing hydroxyl or amino group(s). Despite considerable efforts made in recent years, some fundamental aspects of the SULTs, particularly their ontogeny, cell type/tissue/organ-specific distribution, and physiological relevance, particularly their involvement in drug metabolism and detoxification, still remain poorly understood.

A novel hydroxysteroid-sulfating cytosolic sulfotransferase, SULT3 ST3, from zebrafish: identification, characterization, and ontogenic study.

To establish the zebrafish as a model for investigating the drug metabolism through sulfation, we had embarked on establishing a complete repertoire of the zebrafish Phase II cytosolic sulfotransferases (SULTs). By searching the expressed sequence tag database, a zebrafish cDNA encoding a putative cytosolic sulfotransferase (SULT) was identified. Based on the sequence analysis, this zebrafish SULT was found to belong to the SULT3 gene family.

Characterization and ontogenic study of novel steroid-sulfating SULT3 sulfotransferases from zebrafish.

In vertebrates, sulfation as catalyzed by members of the cytosolic sulfotransferase (SULT) family has been suggested to be involved in the homeostasis of steroids. To establish the zebrafish as a model for investigating how sulfation functions to regulate steroid metabolism during the developmental process, we have embarked on the identification of steroid-sulfating SULTs in zebrafish. By searching the GenBank database, we identified two putative cytosolic SULT sequences from zebrafish, designated SULT3 ST1 and ST2.

Identification and characterization of two novel cytosolic sulfotransferases, SULT1 ST7 and SULT1 ST8, from zebrafish.

Cytosolic sulfotransferases (SULTs) constitute a family of Phase II detoxification enzymes that are involved in the protection against potentially harmful xenobiotics as well as the regulation and homeostasis of endogenous compounds. Compared with humans and rodents, the zebrafish serves as an excellent model for studying the role of SULTs in the detoxification of environmental pollutants including environmental estrogens. By searching the expressed sequence tag database, two zebrafish cDNAs encoding putative SULTs were identified.

Protein SRP68 of human signal recognition particle: identification of the RNA and SRP72 binding domains.

The signal recognition particle (SRP) plays an important role in the delivery of secretory proteins to cellular membranes. Mammalian SRP is composed of six polypeptides among which SRP68 and SRP72 form a heterodimer that has been notoriously difficult to investigate. Human SRP68 was purified from overexpressing Escherichia coli cells and was found to bind to recombinant SRP72 as well as in vitro-transcribed human SRP RNA.