Putative multiadhesive protein from the marine sponge Geodia cydonium: Cloning of the cDNA encoding a fibronectin‐, an SRCR‐, and a complement control protein module

Abstract

Sponges (Porifera) representing the simplest metazoan phylum so far have been thought to possess no basal lamina tissue structures. One major extracellular matrix protein that is also a constitutive glycoprotein of the basal lamina is fibronectin. It was the aim of the present study to identify the native protein from the marine sponge Geodia cydonium and to isolate the corresponding cDNA. In crude extracts from this sponge protein(s) of M(r) of approximately 230 and approximately 210 kDa could be visualized by Western-blotting using an anti-fibronectin [human] antibody. By PCR cloning from a cDNA library of G. cydonium we isolated a cDNA comprising one element of fibronectin, the type-III (FN3) module. The cDNA (2.3 kb long), encoding a 701 amino acid [aa] long putative "multiadhesive protein" termed MAP_GEOCY, was found to contain (i) a fibronectin-, (ii) a scavenger receptor cysteine-rich [SRCR]-, and (iii) a short consensus repeat [SCR] module. The 89 aa long fibronectin module comprises the characteristic topology and conserved aa found in fibronectin type-III (FN3) elements. The SRCR module (101 aa) features the characteristics of group B SRCR molecules. The predominant proteins belonging to this group are the mammalian WC1-, M130-, CD6- and CD5 antigens that probably are involved in immunological reactions. The SCR module (54 aa) shows the characteristics of type III SCR modules found in complement receptors. Phylogenetic analyses performed with all three building blocks of the "multiadhesive protein" showed that the respective sponge modules form independent, possibly basal, lineages in trees that include the corresponding modules from higher metazoan animals. In summary, these data demonstrate for the first time that the phylogenetically oldest Metazoa, the sponges, contain protein modules seen in higher animals in proteins of the extracellular matrix and in molecules involved in cell-mediated immune reactions in vertebrates.

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.…”

The Conserved Scavenger Receptor Cysteine-Rich Superfamily in Therapy and Diagnosis

“…Sponges constitute the oldest and lowest metazoan phylum; within them, Geodia cydonium, from the family Geodiidae, represents the oldest living group (Mü ller et al, 1999). Several alternatively spliced forms of an SRCR group A protein and a group B protein have been identified in G. cydonium (Pancer et al, 1997;Pahler et al, 1998). The group A protein has both membrane-bound and soluble forms, whereas the SRCR domain of MAP_GEOCY, the group B protein, displays high homology with those of CD5 and CD6.…”

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

“…The molecules identified, cloned, and expressed from sponges, mainly from Geodia cydonium and Suberites domuncula, are cell membrane receptors that are not found in fungi, plants, or Protozoa, e.g., the receptor tyrosine kinase (Müller and Schäcke 1996;Wimmer et al 1999a), integrin (Pancer et al 1997a;Wimmer et al 1999b), receptors comprising scavenger receptor cysteine-rich repeats (Pancer et al 1997b;Blumbach et al 1998), a putative multiadhesive basal lamina protein (Pahler et al 1998b), a neuronal-like metabotropic glutamate-like receptor (Perovic et al 1999), and the sponge adhesion molecules with two immunoglobulin-like domains in the extracellular part that display sequence similarity to the human inhibitory receptor Kir or to the T-cell receptor (Blumbach et al 1999;Müller et al 1999b). Furthermore, immune molecules, cytokine-like as well as immune modulatory molecules, identified in sponges, have also not yet been found in nonmetazoan organisms.…”