title: Qualitative and quantitative aspects of 2-5A synthesizing capacity of different marine sponges.
abstract: 2-5A synthetase is an important component of the mammalian antiviral 2-5A system. At present, the existence of 2-5A synthetase in the lowest animals, the marine sponges, has been demonstrated, although this enzyme has not been found in bacteria, yeast or plants. Here, we studied the 2-5A synthesizing capacity and the product profile of a variety of marine sponges belonging to Demospongia subclasses Tetractinomorpha and Ceractinomorpha. The 2-5A synthetase activity varied largely, in the range of four orders of magnitude, depending on the sponge species. Compared with the enzymes of the mammalian 2-5A synthetase family, the most active sponge species exhibited a surprisingly high 2-5A synthetase specific activity. Unlike the mammalian 2-5A synthetases that produce 2-5A oligomers in the presence of a double-stranded RNA activator, the 2-5A synthetase(s) from sponges were active without the addition of dsRNA. The sponge species differed in their product profiles. A novel product pool formed by Chondrosia reniformis was identified as a series of long 2-5A oligomers (up to 17-mers) with the prevalence of heptamers and octamers. The large variability of qualitative and quantitative characteristics of sponge 2-5A synthetases may refer to the occurrence of a variety of 2-5A synthetase isozymes in sponges.
authors.affiliation: Laboratory of Molecular Genetics, National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, 12618 Tallinn, Estonia.
authors.forename: Tõnu
authors.initials: T
authors.lastname: Reintamm
authors.forename: Annika
authors.initials: A
authors.lastname: Lopp
authors.forename: Anne
authors.initials: A
authors.lastname: Kuusksalu
authors.forename: Juhan
authors.initials: J
authors.lastname: Subbi
authors.forename: Merike
authors.initials: M
authors.lastname: Kelve
mesh_terms: D015088:2',5'-Oligoadenylate Synthetase / Q000032:analysis / Q000096:biosynthesis* / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D004789:Enzyme Activation; D007527:Isoenzymes / Q000032:analysis / Q000096:biosynthesis / Q000737:chemistry; D008386:Marine Biology / Q000379:methods; D011161:Porifera / Q000145:classification* / Q000201:enzymology*; D013045:Species Specificity
chemical_list: D007527:Isoenzymes; D000255:Adenosine Triphosphate; D015088:2',5'-Oligoadenylate Synthetase