The A5 antigen, a candidate for the neuronal recognition molecule, has homologies to complement components and coagulation factors.
The A5 antigen is a neuronal cell surface protein of Xenopus presumed to be involved in the neuronal recognition between the optic nerve fibers and the visual centers. Analyses of cDNA clones revealed that the A5 antigen is a class I membrane protein containing two different internal repeats in the extracellular segment. The first repeat bears homology to domain III of complement components C1r and C1s, and the second repeat is homologous to the C1 and C2 domains of coagulation factors V and VIII. The mRNA for the A5 antigen was present in retinal ganglion cells and visual center neurons. Nonneuronal cells in the peripheral and central nervous systems did not express the mRNA for the A5 antigen.
Takagi
S
S
Department of Molecular Biology, Faculty of Science, Nagoya University, Japan.
Hirata
T
T
Agata
K
K
Mochii
M
M
Eguchi
G
G
Fujisawa
H
H
D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D001483:Base Sequence; D001779:Blood Coagulation Factors / Q000235:genetics*; D015152:Blotting, Northern; D003001:Cloning, Molecular; D003165:Complement System Proteins / Q000235:genetics*; D005165:Factor V / Q000235:genetics / Q000378:metabolism; D005169:Factor VIII / Q000235:genetics / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D007106:Immune Sera / Q000276:immunology; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D039942:Neuropilin-1; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014981:Xenopus
D000954:Antigens, Surface; D001779:Blood Coagulation Factors; D007106:Immune Sera; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D039942:Neuropilin-1; D005165:Factor V; D005169:Factor VIII; D003165:Complement System Proteins