title: Structure, function and molecular genetics of human and murine C1r.
abstract: C1r, the enzyme responsible for intrinsic activation of the C1 complex of complement, is a modular serine protease featuring an overall structural organization homologous to those of C1s and the mannan-binding lectin-associated serine proteases (MASPs). This review will initially summarize current information on the structure and function of C1r, with particular emphasis on the three-dimensional structure of its catalytic domain, which provides new insights into the activation mechanism of C1. The second part of this review will focus on recent discoveries dealing with a truncated, C1r-related protein, and the occurrence in the mouse of two isoforms, C1rA and C1rB, exhibiting tissue-specific expression patterns.
authors.affiliation: Institut de Biologie Structurale Jean-Pierre Ebel, Grenoble, France. arlaud@ibs.fr
authors.forename: Gérard J
authors.initials: GJ
authors.lastname: Arlaud
authors.forename: Christine
authors.initials: C
authors.lastname: Gaboriaud
authors.forename: Gérard
authors.initials: G
authors.lastname: Garnier
authors.forename: Antonella
authors.initials: A
authors.lastname: Circolo
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Thielens
authors.forename: Monika
authors.initials: M
authors.lastname: Budayova-Spano
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Fontecilla-Camps
authors.forename: John E
authors.initials: JE
authors.lastname: Volanakis
mesh_terms: D000818:Animals; D015923:Complement C1r / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology*; D003173:Complement C1s / Q000737:chemistry / Q000502:physiology; D003171:Complement Pathway, Classical / Q000502:physiology*; D004789:Enzyme Activation; D006801:Humans; D051379:Mice; D020033:Protein Isoforms; D017433:Protein Structure, Secondary; D013329:Structure-Activity Relationship
chemical_list: D020033:Protein Isoforms; D015923:Complement C1r; D003173:Complement C1s