Characterization of Two Genes Coding for a Similar Four‐Cysteine Motif of the Amino‐Terminal Propeptide of a Sea Urchin Fibrillar Collagen

Journal of Biological Chemistry

Humbert

et al. 2001

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The Sea URchin Fibrillar (SURF) domain is a fourcysteine module present in the amino-propeptide of the sea urchin 2␣ fibrillar collagen chain. Despite numerous international genome and expressed sequence tag projects, computer searches have so far failed to identify similar domains in other species. Here, we have characterized a new sea urchin protein of 2656 amino acids made up of a series of epidermal growth factor-like and SURF modules. From its striking similarity to the modular organization of fibropellins, we called this new protein fibrosurfin. This protein is acidic with a calculated pI of 4.12. Eleven of the 17 epidermal growth factor-like domains correspond to the consensus sequence of calcium-binding type. By Western blot and immunofluorescence analyses, this protein is not detectable during embryogenesis. In adult tissues, fibrosurfin is colocalized with the amino-propeptide of the 2␣ fibrillar collagen chain in several collagenous ligaments, i.e., test sutures, spine ligaments, peristomial membrane, and to a lesser extent, tube feet. Finally, immunogold labeling indicates that fibrosurfin is an interfibrillar component of collagenous tissues. Taken together, the data suggest that proteins possessing SURF modules are localized in the vicinity of mineralized tissues and could be responsible for the unique properties of sea urchin mutable collagenous tissues.Collagens are a large family of extracellular matrix proteins present in all animal phyla. Among the 19 collagen types hitherto identified, five of them, types I-III, V, and XI, constitute the fibrillar collagens (1). Each procollagen molecule is made of three ␣ chains, each of which can be identical or not. Each ␣ chain contains a triple helical region of 1014 amino acids constructed of an uninterrupted series of GXY triplets. Two noncollagenous regions, the amino-and the carboxyl-propeptide flank this domain. During extracellular maturation of procollagen into collagen molecules, the N-and the C-propeptides are generally removed by the action of specific proteases. The resulting collagen molecule consists of a central triple helix flanked by two short non-collagenous segments, the N-and the C-telopeptides (1, 2). Although the size of the central triple helical region is conserved, with one glycine residue for every three amino acids, the sequence of the C-propeptide domain is the most conserved among the ␣ chains. In contrast, the Npropeptide domain is the most variable region among procollagen molecules. Three different N-propeptide configurations have been characterized in vertebrates (3), and a fourth structure has been defined in sea urchin (4). All of them contain a short triple helical region at the carboxyl terminus. In sea urchin, the N-propeptide consists, from the amino to the carboxyl terminus, of a cysteine-rich region or tsp-2 module, 12 repeats of a four-cysteine domain, and a short triple helical region connected to the N-telopeptide. The four-cysteine module or SURF, 1 for Sea URchin Fibrillar, domain has been described for the fi...

Section: The P Lividus Genome Can Potentially Encode Several Proteinmentioning

confidence: 98%

mentioning

confidence: 99%

Characterization of Fibrosurfin, an Interfibrillar Component of Sea Urchin Catch Connective Tissues

Cluzel¹,

Journal of Biological Chemistry

Humbert

et al. 2001

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“…This property has been related to the thin diameter of the fibrils (Linsenmayer et al, 1993;Wu and Eyre, 1995). In the model of Linsenmayer et al (1993), type V molecules are arranged such that their triple-helical domain lies (Lee et al, 1991 ;Exposito et al, 1995). By comparison of the three distinct vertebrate N-propeptide structures and the newly N-propeptide configuration (called structure IV) specific of the sea urchin fibrillar 2a chain, only one subdomain, i.e.…”

Section: Discussionmentioning

confidence: 99%

“…The l a chain corresponds to the vertebrate homolog of the proa2(I) chain (Exposito et al, 1992b), and the 3u and 4a chains correspond to two basement membrane type IV collagen chains (Exposito et al, 1993(Exposito et al, , 1994. By in situ hybridization, it has been reported that the four collagen-related genes are expressed in the mesenchymal cell lineage (D'Alessio et al, 1989(D'Alessio et al, , 1990Wessel et al, 1991 ;Exposito et al, 1994). The two type IV related genes begin to be co-expressed at the blastula stage and the two fibrillar collagen genes at the late gastrula stage.…”

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confidence: 99%

Collagen Fibrillogenesis during Sea Urchin Development

European Journal of Biochemistry

Exposito

Garrone

1997

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The sea urchin 2a fibrillar collagen chain has a unique amino-propeptide structure with several repetitions of a still unknown 140-145-amino-acid, four-Cys module called SURF (for sea urchin fibrillar module). To follow the expression of the amino-propeptide of the 2cr chain and assign a function to this domain, we have overproduced in Escherichiu culi several recombinant proteins corresponding either to the amino-propeptide or to the amino-telopeptide. Monoclonal andor polyclonal antibodies against these recombinant proteins allowed us to observe a similar tissue distribution during the first stages of development. A signal is first observed at the prism stage as intracellular spots in mesenchymal cells. In plutei, immunofluorescence staining is observed around the skeleton spicules and as a thin meshwork surrounding the mesenchymal cells. At the ultrastructural level, and using antibodies against the amino-propeptide, gold particles are observed at the surface of 25 nm thin periodic fibrils. By rotary shadowing, these fibrils show a brush-bottle aspect, exhibiting at their surface numerous periodically distributed thin rods ended by a small globule. These data indicate that the amino-propeptide is maintained during fibrillogenesis.As previously suggested, the retention of the amino-propeptide could play an important role in regulation of the fibril growth. We propose that the important region of this amino-propeptide in the widely encountered 25-nm-diameter fibrils is the short triple-helical segment. The globular part of the amino-propeptide will not only restrict the fibril growth but also interact with other neighbouring components and playing, as suspected from our immunofluorescence studies, a function during the spiculogenesis of the sea urchin embryo.Keywords: sea urchin; collagen ; fibrillogenesis; amino-propeptide.In higher vertebrates, 19 collagen types have been characterized, which from the protein structure and the related gene organization can be divided into several groups (for a recent review, see Prockop and Kivirikko, 1995). One of these comprises the fibrillar collagens which aggregate into the periodic fibers. Five types of fibrillar collagens (types I, 11, 111, V and XI) have been characterized and nine genetically distinct a chains can combine in the formation of the procollagen molecules which can be homotrimeric or heterotrimeric, but also heterotypic (V/XI) (Niyibizi and Eyre, 1989;Prockop and Kivirikko, 1995). Each procollagen molecule is composed of three a chains, each of which contains a perfect triple-helical domain made of an uninterrupted series of Gly-Xaa-Yaa amino acid triplets flanked by two non-collageneous domains, the amino-(N-) and the carboxy-(C-) propeptide. Two short segments, the N-and C-telopeptide respectively, link the N-and the C-propeptide to the central triple-helical domain. During the extracellular maturation of the procollagen molecules, the two propeptide regions are generally removed by the action of two specific proteases (the N-and the C-proteinase), and ...

“…Moreover, traces of a homotrimeric 1␣ chain have been described in the sea urchin Paracentrotus lividus (9). The complete primary structure of these two fibrillar collagen chains has been characterized in the sea urchin Strongylocentrotus purpuratus (10,11), whereas partial sequences have been described in P. lividus (12)(13)(14) and Hemicentrotus pulcherrimus (15). The 2␣ chain presents a large N-propeptide region including 12 repeats of an 140 -145 amino acid module that we have named SURF 1 for sea urchin fibrillar module (14).…”

mentioning

confidence: 99%

Distinct Maturations of N-propeptide Domains in Fibrillar Procollagen Molecules Involved in the Formation of Heterotypic Fibrils in Adult Sea Urchin Collagenous Tissues

Cluzel

Journal of Biological Chemistry

Garrone

et al. 2004

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We have characterized the primary structure of a new sea urchin fibrillar collagen, the 5␣ chain, including nine repeats of the sea urchin fibrillar module in its N-propeptide. By Western blot and immunofluorescence analyses, we have shown that 5␣ is co-localized in adult collagenous ligaments with the 2␣ fibrillar collagen chain and fibrosurfin, two other extracellular matrix proteins possessing sea urchin fibrillar modules. At the ultrastructural level, the 5␣ N-propeptide is detected at the surface of fibrils, suggesting the retention of this domain in mature collagen molecules. Biochemical characterization of pepsinized collagen molecules extracted from the test tissue (the endoskeleton) together with a matrix-assisted laser desorption ionization timeof-flight analysis allowed us to determine that 5␣ is a quantitatively minor fibrillar collagen chain in comparison with the 1␣ and 2␣ chains. Moreover, 5␣ forms heterotrimeric molecules with two 1␣ chains. Hence, as in vertebrates, sea urchin collagen fibrils are made up of quantitatively major and minor fibrillar molecules undergoing distinct maturation of their N-propeptide regions and participating in the formation of heterotypic fibrils.Among the components of extracellular matrix, collagens are the most abundant of the glycoproteins. In vertebrates, 27 collagen types have been identified (1-4). All of them consist of three identical or different ␣ chains that contain at least one collagenous or triple helical segment, consisting of repeating Gly-Xaa-Xaa triplets. The collagen domains of the three ␣ chains coil around each other into a triple helical structure. The fibrillar collagens, including types I-III, V, and XI, are the best known, and their precursor ␣ chains consist of a main triple helix made up of ϳ338 Gly-Xaa-Xaa triplets flanked by two non-collagenous regions containing the N-and the C-propeptides. During maturation of procollagens into collagen molecules, the two propeptide domains are generally removed by the action of specific proteinases (1). The resulting collagen molecules participate in the formation of supramolecular structures called fibrils. The invertebrate fibrillar ␣ chains so far described present the same overall structure as that of their vertebrate counterparts (5).In different sea urchin species, studies have indicated the presence of two fibrillar ␣ chains (1␣ and 2␣) involved in the formation of heterotrimeric molecules [(1␣) 2 -2␣] (6 -8). Moreover, traces of a homotrimeric 1␣ chain have been described in the sea urchin Paracentrotus lividus (9). The complete primary structure of these two fibrillar collagen chains has been characterized in the sea urchin Strongylocentrotus purpuratus (10,