Expression cloning of a receptor for C5a anaphylatoxin on differentiated HL-60 cells.
Article Details
- CitationCopy to clipboard
Boulay F, Mery L, Tardif M, Brouchon L, Vignais P
Expression cloning of a receptor for C5a anaphylatoxin on differentiated HL-60 cells.
Biochemistry. 1991 Mar 26;30(12):2993-9.
- PubMed ID
- 2007135 [ View in PubMed]
- Abstract
A cDNA clone encoding the human C5a anaphylatoxin receptor has been isolated by expression cloning from a CDM8 expression library prepared from mRNA of human myeloid HL-60 cells differentiated to the granulocyte phenotype with dibutyryladenosine cyclic monophosphate. The cDNA clone was able to transfer to COS-7 cells the capacity to specifically bind iodinated human recombinant C5a. The cDNA was 2.3 kb long, with an open reading frame encoding a 350-residue polypeptide. Cross-linking of iodinated C5a to the plasma membrane of transfected COS cells revealed a complex with an apparent molecular mass of 52-55 kDa, similar to that observed for the constitutively expressed receptor in differentiated HL-60 cells or human neutrophils. Although differentiated HL-60 cells display a single class of binding sites, with a dissociation constant of approximately 800-900 pM, the C5a-R cDNA, expressed in COS cells, generates both high-affinity (1.7 nM) and low-affinity (20-25 nM) receptors. Sequence comparison established that the degree of sequence identity between the C5a receptor and the N-formylpeptide receptor is 34%.