Biochemical and Morphological Studies on Collagens of Horny Sponges. Ircinia Filaments Compared to Spongines

Junqua, Simone; Robert, L.; Garrone, R.; Ceccatty, M. Pavans de; Vacelet, Jean

doi:10.3109/03008207409152244

Cited by 71 publications

(63 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is frequently observed in Emfla as well as in nonfibrillar sponge collagen (21) and in vertebrate type IV collagen (39,40). Most of these lysine residues could be hydroxylated and subsequently glycosylated since sponge collagens are highly glycosylated (20,41). The presence of an imperfection (Gly-Xaa-Yaa-Zaa) in the triple-helical domain is exceptional for fibrillar collagen.…”

Section: Discussionmentioning

confidence: 96%

Characterization of a fibrillar collagen gene in sponges reveals the early evolutionary appearance of two collagen gene families.

Exposito¹,

Garrone²

1990

Proc. Natl. Acad. Sci. U.S.A.

131

View full text Add to dashboard Cite

We have characterized cDNA and genomic clones coding for a sponge collagen. The partial cDNA has an open reading frame encoding 547 amino acid residues. The conceptual translation product contains a probably incomplete triple-helical domain (307 amino acids) with one Gly-Xaa-YaaZaa imperfection in the otherwise perfect Gly-Xaa-Yaa repeats and a carboxyl propeptide (240 amino acids) that includes 7 cysteine residues. Amino acid sequence comparisons indicate that this sponge collagen is homologous to vertebrate and sea urchin fibrillar coliagens. Partial characterization of the corresponding gene reveals an intron-exon organization clearly related to the fibrillar collagen gene family. The exons coding for the triple-helical domain are 54 base pairs (bp) or multiples thereof, except for a 57-bp exon containing the Gly-Xaa-YaaZaa coding sequence and for two unusual exons of 126 and 18 bp, respectively. This latter 18-bp exon marks the end of the triple-helical domain, contrary to the other known ribriflar collagen genes that contain exons coding for the junction between the triple-helical domain and the carboxyl propeptide. Compared to other fibrillar collagen genes, the introns are remarkably small. Hybridization to blotted RNAs established that the gene transcript is 4.9 kilobases. Together with previous results that showed the existence of a nonfibrillar collagen in the same species, these data demonstrate that at least two collagen gene families are represented in the most primitive metazoa.Collagens are multidomain, interactive proteins that constitute the main extracellular component of all multicellular animals (1). So far, 13 different collagen types have been described in vertebrates, most of them forming polymeric structures or being closely associated with other collagenous polymers. Collagen molecules are made of three a chains, which may or may not be identical. They are characterized by the presence of triple-helical domains, which contain GlyXaa-Yaa repeats, that are essential for helix formation (2). More than 20 genes encode the different a chains. With the exception of the gene coding for type X collagen (3, 4), the described collagen coding genes have a complex exon-intron organization. Among them, the genes coding for the fibrilforming collagens (types I, II, III, V, and XI) have a homologous organization (5-8) with, in particular, triple-helix coding exons related to a 54-base-pair (bp) unit. These exons are believed to have evolved from an ancestral unit of 54 bp encoding six Gly-Xaa-Yaa repeats (9). The nonfibrillar collagen genes examined so far have more variable structures even though a few 54-bp exon units have been described (10-13).Very few data have been reported on the collagen gene organization in invertebrates. Variable exon sizes have been found in the nonfibrillar collagen genes, either in Drosophila melanogaster (14)(15)(16) or in Caenorhabditis elegans (17, 18), contrary to the multiple 54-bp motif described recently in a fibrillar collagen gene of the sea urchin Paracen...

show abstract

Section: Discussionmentioning

confidence: 96%

Characterization of a fibrillar collagen gene in sponges reveals the early evolutionary appearance of two collagen gene families.

Exposito¹,

Garrone²

1990

Proc. Natl. Acad. Sci. U.S.A.

131

View full text Add to dashboard Cite

show abstract

“…Collagen fibrils are synthesized in several cell types (Simpson 1984) with the lophocytes as the prevailing cells (Garrone 1978); in addition, spongocytes have been identified which secrete spongin fibers that contribute to the synthesis of the horny skeleton (Garrone 1978). According to the chemical analysis, spongin should be considered as a collagen-like molecule (Junqua et al 1974). Since only one gene coding for collagen has been identified in sponges, it remains open if spongin is only a processed form of collagen.…”

Section: Proposed Pathway For Spicule Formationmentioning

confidence: 99%

Molecular Mechanism of Spicule Formation in the Demosponge Suberites domuncula: Silicatein-Collagen-Myotrophin

Müller¹,

Krasko²,

Pennec³

et al. 2003

Silicon Biomineralization

View full text Add to dashboard Cite

“…Other organizations have been described: long (IO~m), symmetrical filaments (Fig. 22) with pear-shaped extremities in the genus Ircinia Junqua et al, 1974), and spiculoids, which are regular structures shaped like inorganic spicules (see Garrone, 1978 for details). A last spongin formation is the coat of gemmules (see Simpson et al, this volume).…”

Section: The Ever Present Collagen Fibrilsmentioning

confidence: 99%

The Collagen of the Porifera

Garrone

1985

Biology of Invertebrate and Lower Vertebrate Collagens

View full text Add to dashboard Cite

The phylum Porifera is not a widely known group of animals. Although the skeleton of certain species, the bath sponges, is a common object, most people have no idea that it represents the collagenous skeleton of an animal. Even for Biologists, the sponges are poorly documented and their collagen remains one of the most puzzling in the animal kingdom. However, there is now an increasing interest in the biology of these primitive and fascinating multicellular animals and several recent books are available (Bergquist, 1978;Brien et al., 1973;Garrone, 1978; Simpson, 1984). WHAT THE SPONGES ARE, WHAT THEY ARE NOT General featuresThe animal nature of sponges was firmly established in the early nineteenth century and they are now considered as one of the most primitive multicellular animals, the first metazoans. The phylum Porifera, relatively small, comprises less than 6000 species, all being aquatic. Sponges have colonized all the seas and, for freshwater species, lakes and streams. They show a great diversity in colours, size (from a few millimeters to more than a meter) and shape. According to the species, they can be erect and form cups, fans, trees or finger-like structures; they can spread over the substratum or grow in a globular fashion. They are sedentary, filterfeeding animals and they reproduce by sexual mechanisms or asexual processes involving in certain cases special structures, the gemmules (see Simpson et al., this volume) or even by regeneration. They possess an apparent simplicity in their cellular structures (Simpson, 1984) which makes them a very suitable system for experimental studies, particularly in the field of cell recognition.

show abstract

Biochemical and Morphological Studies on Collagens of Horny Sponges. Ircinia Filaments Compared to Spongines

Cited by 71 publications

References 14 publications

Characterization of a fibrillar collagen gene in sponges reveals the early evolutionary appearance of two collagen gene families.

Characterization of a fibrillar collagen gene in sponges reveals the early evolutionary appearance of two collagen gene families.

Molecular Mechanism of Spicule Formation in the Demosponge Suberites domuncula: Silicatein-Collagen-Myotrophin

The Collagen of the Porifera

Contact Info

Product

Resources

About