title: Caspase-mediated apoptosis in sponges: cloning and function of the phylogenetic oldest apoptotic proteases from Metazoa.
abstract: Sponges (phylum Porifera) represent the phylogenetically oldest metazoan phylum. These animals have complex cell adhesion and powerful immune systems which allow the formation of a distinct body plan. Consequently, an apoptotic machinery has to be predicted that allows sponges to eliminate unwanted cells accumulating during development. With the marine sponge Geodia cydonium, it is shown that allografts of these animals undergo apoptosis as demonstrated by apoptotic DNA fragmentation. Extracts from allografts contain an enzymic activity characteristic for caspases; as substrate to determine the cleavage activity, Ac-DEVD-AMC was applied. cDNAs encoding predicted caspase-3-related proteins were isolated; they comprise the characteristic structure known from caspases of other metazoan phyla. The two cDNAs are assumed to originate from one gene by alternative splicing; the longer form comprises a caspase recruitment domain (CARD), whereas the shorter one is missing CARD. The expression of sponge caspase genes is up-regulated during allograft rejection. In vivo incubation experiments with Ac-DEVD-CHO (a caspase-3 inhibitor) showed a reduction of apoptotic DNA fragmentation, whereas Ac-LEHD-CHO (an inhibitor of caspase-9) caused no effect. It is concluded, that for the establishment of the metazoan body plan, both the adhesion molecules and the apoptotic molecules (described here) were essential prerequisites.
authors.affiliation: Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universität Mainz, Duesbergweg 6, 55099, Mainz, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Wiens
authors.forename: Anatoli
authors.initials: A
authors.lastname: Krasko
authors.forename: Sanja
authors.initials: S
authors.lastname: Perovic
authors.forename: Werner E G
authors.initials: WE
authors.lastname: Müller
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D053148:Caspase 3; D061945:Caspase Inhibitors; D020169:Caspases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003374:Coumarins / Q000494:pharmacology; D010450:Endopeptidases / Q000235:genetics / Q000502:physiology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000494:pharmacology; D010802:Phylogeny; D011161:Porifera / Q000235:genetics / Q000502:physiology*; D016415:Sequence Alignment
chemical_list: C112287:Ac-aspartyl-glutamyl-valyl-aspartyl-aminomethylcoumarin; D061945:Caspase Inhibitors; D003374:Coumarins; D004791:Enzyme Inhibitors; D007527:Isoenzymes; D009842:Oligopeptides; C099158:acetyl-aspartyl-glutamyl-valyl-aspartal; D010450:Endopeptidases; D053148:Caspase 3; D020169:Caspases