Alternative roles for CD59.
CD59 was first identified as a regulator of the terminal pathway of complement, which acts by binding to the C8/C9 components of the assembling membrane attack complex (MAC), to inhibit formation of the lytic pore. Structurally, CD59 is a small, highly glycosylated, GPI-linked protein, with a wide expression profile. Functionally, the role of CD59 in complement regulation is well-defined but studies have also shown clear evidence for signalling properties, which are linked to its glycophosphatidyl inositol (GPI) anchor and its location within lipid rafts. Cross-linking of CD59 using specific monoclonal antibodies drives both calcium release and activation of lipid-raft associated signalling molecules such as tyrosine kinases. These observations clearly show that CD59 exhibits roles independent of its function as a complement inhibitor. In this review, we examine the progression of research in this area and explore the alternative functions of CD59 that have recently been defined.
Kimberley
Fiona C
FC
Complement Biology Group, Department of Medical Biochemistry and Immunology, Henry Wellcome Building, School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK.
Sivasankar
Baalasubramanian
B
Paul Morgan
B
B
D000818:Animals; D001402:B-Lymphocytes / Q000502:physiology; D001426:Bacterial Proteins / Q000502:physiology; D001430:Bacteriocins; D018801:CD2 Antigens / Q000502:physiology; D018957:CD59 Antigens / Q000502:physiology*; D037282:Calreticulin / Q000502:physiology; D006801:Humans; D007694:Killer Cells, Natural / Q000502:physiology; D008070:Lipopolysaccharides / Q000494:pharmacology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000502:physiology
D001426:Bacterial Proteins; D001430:Bacteriocins; D018801:CD2 Antigens; D018957:CD59 Antigens; D037282:Calreticulin; D008070:Lipopolysaccharides; C403910:intermedilysin protein, Streptococcus intermedius