An Ancient Lectin-Dependent Complement System in an Ascidian: Novel Lectin Isolated from the Plasma of the Solitary Ascidian, <i>Halocynthia roretzi</i>

Sekine, Hideharu; Kenjo, Akira; Azumi, Kaoru; Ohi, Gota; Takahashi, Minoru; Kasukawa, Reiji; Ichikawa, Narumi; Nakata, Munehiro; Mizuochi, Tsuguo; Matsushita, Misao; Endo, Yuichi; Fujita, Teizo

doi:10.4049/jimmunol.167.8.4504

Cited by 121 publications

(70 citation statements)

References 34 publications

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“…Recently, the mannose-binding lectin-associated serine protease (MASP) (Ji et al, 1997), and C3 have been identified in the invertebrates like urochordate, and the origin of lectin-dependent pathway is traced back to the invertebrates (Sekine et al, 2001). Therefore, the possibility cannot be ruled out that the lectin pathway is present in amphioxus.…”

Section: Discussionmentioning

confidence: 90%

Presence and Characterization of Complement-like Activity in the Amphioxus Branchiostoma belcheri tsingtauense

Zhang

Wang

et al. 2003

Zoological Science

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Section: Discussionmentioning

confidence: 90%

Presence and Characterization of Complement-like Activity in the Amphioxus Branchiostoma belcheri tsingtauense

Zhang

Wang

et al. 2003

Zoological Science

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“…In this phylum, several components of a primitive lectin-dependent complement system have been characterized, including ficolins and mannose-binding like proteins. It should be noted that the collagenous region of ascidian ficolins is shorter than that of vertebrate ficolins , and that the collagenous region of MBL is absent in the Ascidian MBL-like proteins characterized so far (Sekine et al, 2001). …”

Section: General Commentsmentioning

confidence: 99%

Evolution of collagens

et al. 2002

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The extracellular matrix is often defined as the substance that gives multicellular organisms (from plants to vertebrates) their structural integrity, and is intimately involved in their development. Although the general functions of extracellular matrices are comparable, their compositions are quite distinct. One of the specific components of metazoan extracellular matrices is collagen, which is present in organisms ranging from sponges to humans. By comparing data obtained in diploblastic, protostomic, and deuterostomic animals, we have attempted to trace the evolution of collagens and collagen-like proteins. Moreover, the collagen story is closely involved with the emergence and evolution of metazoa. The collagen triple helix is one of numerous modules that arose during the metazoan radiation which permit the formation of large multimodular proteins. One of the advantages of this module is its involvement in oligomerization, in which it acts as a structural organizer that is not only relatively resistant to proteases but also permits the creation of multivalent supramolecular networks. Anat Rec 268: 302-316, 2002.

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“…The binding of LC1q to GlcNAc-BSA was inhibited by GlcNAc and N-acetylmannosamine, but not by the other carbohydrates used. Next, we examined whether the LC1q-MASP-A complex activated lamprey C3, because ascidian MBL-like protein (glucosebinding lectin), upon association with MASPs, activates C3, the key component of the complement system (9). As shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Origin of the classical complement pathway: Lamprey orthologue of mammalian C1q acts as a lectin

Matsushita

Endo

et al. 2004

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

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131

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The lectin complement pathway in innate immunity is closely related to the classical complement pathway in adaptive immunity, with respect to the structures and functions of their components. Both pathways are initiated by complexes consisting of collagenous proteins and serine proteases of the mannose-binding lectin (MBL)-associated serine protease (MASP)͞C1r͞C1s family. It has been speculated that the classical pathway emerged after the lectin pathway, and that the activation mechanism of the latter was partially conserved. The classical and lectin pathways can be traced back to at least cartilaginous fish and ascidian (urochordata), respectively. To elucidate the evolution of the complement system, we isolated and characterized a GlcNAc-binding lectin from sera of lamprey (agnathans), the most primitive vertebrate that lacks the classical pathway. Lamprey GlcNAc-binding lectin was an oligomer consisting of 24-kDa subunits. cDNA and phylogenetic analyses revealed that the lamprey GlcNAc-binding lectin is an orthologue of mammalian C1q, a collagenous subcomponent of the first component involved in binding to immunoglobulins in the classical pathway. Lamprey C1q copurified with MASP-A, a serine protease of the MASP͞C1r͞C1s family, which exhibited proteolytic activity against lamprey C3. Surface plasmon resonance analysis showed that lamprey C1q specifically bound to GlcNAc, but not various other carbohydrates tested. These results suggest that C1q may have emerged as a lectin and may have functioned as an initial recognition molecule of the complement system in innate immunity before the establishment of adaptive immunity such as immunoglobulins in the cartilaginous fish.

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An Ancient Lectin-Dependent Complement System in an Ascidian: Novel Lectin Isolated from the Plasma of the Solitary Ascidian, Halocynthia roretzi

Cited by 121 publications

References 34 publications

Presence and Characterization of Complement-like Activity in the Amphioxus Branchiostoma belcheri tsingtauense

Presence and Characterization of Complement-like Activity in the Amphioxus Branchiostoma belcheri tsingtauense

Evolution of collagens

Origin of the classical complement pathway: Lamprey orthologue of mammalian C1q acts as a lectin

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