CD46 (membrane cofactor protein of complement, measles virus receptor): structural and functional divergence among species (review).
Human CD46 was identified as a complement regulator and was later shown to be a measles virus receptor. The ubiquitous distribution profile of CD46 accounted for systemic measles infection and general protection of host tissue/organs from autologous complement. A similar ubiquitous distribution was observed for swine and simian CD46 homologues based upon subsequent cDNA cloning and Northern analysis, reinforcing the roles of CD46. In contrast, recent cDNA cloning and distribution analyses of murine and guinea-pig CD46 revealed the predominant expression of these rodent CD46 homologues in the testis, especially in mature testicular germ cells. These results do not support the established functions of human CD46 but support the hypothesis that CD46 on sperm serves as a fertilization-related adhesion molecule toward eggs. Here, we review the structure, function and distribution of human CD46 and discuss the possible differences between human CD46 and its homologues recently cloned from a variety of non-human primates and other animals.
Seya
T
T
Department of Immunology, Osaka Medical Center for Cancer and Cardiovascular Diseases, Higashinari-ku, Osaka 537, Japan.
Nomura
M
M
Murakami
Y
Y
Begum
N A
NA
Matsumoto
M
M
Nagasawa
S
S
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D003167:Complement Activation / Q000276:immunology; D003169:Complement Inactivator Proteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D017124:Conserved Sequence / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D008459:Measles virus; D051916:Membrane Cofactor Protein; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D020033:Protein Isoforms / Q000235:genetics; D011991:Receptors, Virus / Q000235:genetics / Q000276:immunology; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013045:Species Specificity
D015703:Antigens, CD; C497857:CD46 protein, human; D003169:Complement Inactivator Proteins; D051916:Membrane Cofactor Protein; D008562:Membrane Glycoproteins; D020033:Protein Isoforms; D011991:Receptors, Virus