Isolation and characterization of a cDNA encoding a potential morphogen from the marine sponge Geodia cydonium, that is conserved in higher Metazoans

Abstract

Species belonging to the lowest metazoan phylum, the sponges (Porifera), exhibit a surprisingly complex and multifaceted Bauplan (body plan). Recently, key molecules have been isolated from sponges which demonstrate that the cells of these animals are provided with characteristic metazoan adhesion and signal transduction molecules, allowing tissue formation. In order to understand which factors control the spatial organization of these cells in the sponge body plan, we screened for a cDNA encoding a soluble modulator of the behaviour of endothelial cells. A cDNA encoding a putative protein, which is highly similar to the human and mouse endothelial monocyte-activating polypeptide (EMAP) II has been isolated from a library of the marine sponge Geodia cydonium. The sponge EMAP-related polypeptide (EMAPR) has been termed EMAPR1_GC. The full-length cDNA clone, GCEMAPR1, has a size of 592 nucleotides (nt) and contains a 447 nt-long potential open reading frame; the molecular weight (MW) of the deduced amino acid sequence, 16,499 Da, is close to that of mature mammalian EMAP II (ca. 18 kDa). The sponge polypeptide is also closely related to a deduced polypeptide from the cosmid clone F58B3 isolated from Caenorhabditis elegans. A phylogenetic analysis revealed that the sponge and the nematode EMAPR molecules form a cluster which is significantly separated from the corresponding mammalian EMAP molecules. The function of the first cloned putative soluble modulator of endothelial cells in sponges remains to be determined.

Increased expression of the potential proapoptotic molecule DD2 and increased synthesis of leukotriene B4 during allograft rejection in a marine sponge

“…10 In line with these studies it could be clarified, mainly from results with the marine sponges Suberites domuncula and Geodia cydonium, that Porifera have molecules similar to those known from the mammalian innate immune system, such as molecules containing scavenger receptor cysteine-rich domains, 11,12 cytokine-like molecules 13 or members of the (2'-5')oligoadenylate pathway. 14 ± 16 Furthermore, it could also be shown that`precursors' of the second type of immune response in mammals, the adaptive immune system, are present in sponges.…”

Molecular Evolution of Apoptotic Pathways: Cloning of Key Domains from Sponges (Bcl-2 Homology Domains and Death Domains) and Their Phylogenetic Relationships

“…Their expression is upregulated during fusion and rejection reactions. Among them are the allograft inflammatory factor, the (2Ј-5Ј)oligoadenylate synthetase , and a potential morphogen (Pahler et al 1998a).…”

Identification of the reaction products of (2′‐5′)oligoadenylate synthetase in the marine sponge

“…At present it can be postulated that the an (2′-5′)A system is involved in a cytokine-mediated pathway and/or in the protection system against viruses, present in the marine environment. The existence of cytokines or related molecules has been shown in sponges [14] and the presence of viruses in the marine milieu is well documented [56]. Studies are in progress to identify further components of the (2′-5′)A system in sponges and to elucidate the structure of the sponge (2′-5′)A synthetase gene(s).…”

“…integrin receptor [2], collagen [3] or galectin [4,5]), cell-surface receptors (tyrosine kinase receptor [6]), elements of the sensory system (crystallin [7], metabotropic glutamate receptor [8]) and homologs/modules of an immune system (immunoglobulin-like domains [9], scavenger receptor cysteine-rich domains and short consensus repeats [10], Rh-like protein [11]). These molecules were found to display high similarity to sequences from members of higher metazoan phyla [12].Recently a cDNA encoding a putative cytokine, the endothelial monocyte-activating polypeptide [13], was identified in G. cydonium [14]. The physiological role of this factor in sponges is not known.…”

“…Recently a cDNA encoding a putative cytokine, the endothelial monocyte-activating polypeptide [13], was identified in G. cydonium [14]. The physiological role of this factor in sponges is not known.…”