New enzyme research findings from University of Puerto Rico published
2009 AUG 3 - (NewsRx.com) -- According to recent research from the United States, "RNA editing by adenosine deamination is particularly prevalent in the squid nervous system. We hypothesized that the squid editing enzyme might contain structural differences that help explain this phenomenon." "As a first step, a squid adenosine deaminase that acts on RNA (sqADAR2a) cDNA and the gene that encodes it were cloned from the giant axon system. PCR and RNase protection assays showed that a splice variant of this clone ( sqADAR2b) was also expressed in this tissue. Both versions are homologous to the vertebrate ADAR2 family. sqADAR2b encodes a conventional ADAR2 family member with an evolutionarily conserved deaminase domain and two double-stranded RNA binding domains (dsRBD). sqADAR2a differs from sqADAR2b by containing an optional exon that encodes an ''extra'' dsRBD. Both splice variants are expressed at comparable levels and are extensively edited, each in a unique pattern. Recombinant sqADAR2a and sqADAR2b, produced in Pichia pastoris, are both active on duplex RNA. Using a standard 48-h protein induction, both sqADAR2a and sqADAR2b exhibit promiscuous self-editing; however, this activity is particularly robust for sqADAR2a. By decreasing the induction time to 16 h, self-editing was mostly eliminated. We next tested the ability of sqADAR2a and sqADAR2b to edit two K+ channel mRNAs in vitro. Both substrates are known to be edited in squid. For each mRNA, sqADAR2a edited many more sites than sqADAR2b," wrote J.P. Palavicini and colleagues, University of Puerto Rico. The researchers concluded: "These data suggest that the ''extra'' dsRBD confers high activity on sqADAR2a." Palavicini and colleagues published their study in RNA - a Publication of the RNA Society (An extra double-stranded RNA binding domain confers high activity to a squid RNA editing enzyme. RNA - a Publication of the RNA Society, 2009;15(6):1208-1218). For additional information, contact J.J.C. Rosenthal, University of Puerto Rico, Institute Neurobiology, Medical Science Campus, San Juan, PR 00901, USA. Publisher contact information for the journal RNA - a Publication of the RNA Society is: Cold Spring Harbor Laboratory Press, Publications Dept., 500 Sunnyside Blvd., Woodbury, NY 11797-2924, USA. Keywords: United States, San Juan, Adenosine, Adenosine Deaminase, Deaminase, Drugs, Enzyme Research, Enzymes, Enzymology, Pharmaceuticals, Proteins, Proteomics, Rnase, Therapy, Treatment, University of Puerto Rico. This article was prepared by Biotech Business Week editors from staff and other reports. Copyright 2009, Biotech Business Week via NewsRx.com.
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