C1q and tumor necrosis factor superfamily: modularity and versatility.
C1q is the target recognition protein of the classical complement pathway and a major connecting link between innate and acquired immunity. As a charge pattern recognition molecule of innate immunity, C1q can engage a broad range of ligands via its globular (gC1q) domain and modulate immune cells, probably via its collagen region. The gC1q signature domain, also found in many non-complement proteins, has a compact jelly-roll beta-sandwich fold similar to that of the multifunctional tumor necrosis factor (TNF) ligand family. The members of this newly designated 'C1q and TNF superfamily' are involved in processes as diverse as host defense, inflammation, apoptosis, autoimmunity, cell differentiation, organogenesis, hibernation and insulin-resistant obesity. This review is an attempt to draw structural and functional parallels between the members of the C1q and TNF superfamily.
Kishore
Uday
U
Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Headington, Oxford, UK, OX3 9DS. ukishore@hammer.imm.ox.ac.uk <ukishore@hammer.imm.ox.ac.uk>
Gaboriaud
Christine
C
Waters
Patrick
P
Shrive
Annette K
AK
Greenhough
Trevor J
TJ
Reid
Kenneth B M
KB
Sim
Robert B
RB
Arlaud
Gerard J
GJ
D000595:Amino Acid Sequence; D000818:Animals; D015922:Complement C1q / Q000737:chemistry* / Q000276:immunology*; D019418:Evolution, Chemical; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D020836:Protein Structure, Quaternary; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein; D013329:Structure-Activity Relationship; D014409:Tumor Necrosis Factor-alpha / Q000737:chemistry* / Q000276:immunology*
D014409:Tumor Necrosis Factor-alpha; D015922:Complement C1q