Nonspecific cytotoxic cell receptor protein-1: a novel (predicted) type III membrane receptor on the teleost equivalent of natural killer cells recognizes conventional antigen.
The phylogenetic model for "conventional" antigen recognition by NK cells may be a protein (NCCRP-1) recently identified from catfish nonspecific cytotoxic cells (NCC). NCCRP-1 may be a Type III membrane protein. The antigen binding domain was identified by competition experiments using synthetic peptides. Within this domain, a 38-mer peptide (aa 104-140) inhibited NCC killing of IM-9, HL-60, NC-37, U937, and MOLT-4 target cells. Biotinylated 38-mer also bound to IM-9 target cells. A mab which inhibited conjugate formation between NCC and target cells also bound to the 38-mer. Nonbiotinylated 38-mer inhibited mab 5C6 binding to immobilized homologous biotinylated peptide in cold competition ELISA experiments. Peptide 104-140 was truncated into two peptides. Amino acid 104-119 bound to (68%) and inhibited lyis of IM-9 target cells, whereas aa 120-140 had no activity. A predicted structure-function algorithm suggested an N-terminal domain containing BOX-1 motifs for cytokine activation; a C-terminal domain containing abundant phosphorylation sites (i.e., Y, S, and T amino acids); and an extracellular antigen binding domain.
Department of Medical Microbiology and Parasitology, College of Veterinary Medicine, University of Georgia, Athens 30602, USA.
D L
DL
Evans
J H
JH
Leary
L
L
Jaso-Friedmann
D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D000941:Antigens / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D002397:Catfishes / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry / Q000235:genetics; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007694:Killer Cells, Natural / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D011946:Receptors, Antigen / Q000737:chemistry / Q000145:classification / Q000378:metabolism*; D013329:Structure-Activity Relationship
D000911:Antibodies, Monoclonal; D000941:Antigens; D000939:Epitopes; D010455:Peptides; D011946:Receptors, Antigen; C110644:nonspecific cytotoxic cell receptor protein 1