Cloning and characterization of cDNAs encoding the complete sequence of decay-accelerating factor of human complement

M. E. Medof, D. M. Lublin, V. M. Holers, D. J. Ayers, R. R. Getty, J. F. Leykam, J. P. Atkinson, M. L. Tykocinski

Research output: Contribution to journalArticlepeer-review

191 Scopus citations

Abstract

cDNAs encoding the complement decay-accelerating factor (DAF) were isolated from HeLa and differentiated HL-60 λgt cDNA libraries by screening with a codon preference oligonucleotide corresponding to DAF NH2-terminal amino acids 3-14. The composite cDNA sequence showed a 347-amino acid protein preceded by an NH2-terminal leader peptide sequence. The translated sequence beginning at the DAF NH2 terminus encodes four contiguous ≃61-amino acid long repetitive units of internal homology. The repetitive regions contain four conserved cysteines, one proline, one glycine, one glycine/alanine, four leucines/isoleucines/valines, one serine, three tyrosines/phenylalanines, and one tryptophan and show striking homology to similar regions previously identified in factor B, C2, C4 binding protein, factor H, C1r, factor XIII, interleukin 2 receptor, and serum β2-glycoprotein I. The consensus repeats are attached to a 70-amino acid long segment rich in serine and threonine (potential O-glycosylation sites), which is in turn followed by a stretch of hydrophobic amino acids. RNA blot analysis of HeLa and HL-60 RNA revealed three DAF mRNA species of 3.1, 2.7, and 2.0 kilobases. The results indicate that portions of the DAF gene may have evolved from a DNA element common to the above proteins, that DAF cDNA predicts a COOH-terminal anchoring polypeptide, and that distinct species of DAF message are elaborated in cells.

Original languageEnglish
Pages (from-to)2007-2011
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume84
Issue number7
DOIs
StatePublished - 1987

Fingerprint

Dive into the research topics of 'Cloning and characterization of cDNAs encoding the complete sequence of decay-accelerating factor of human complement'. Together they form a unique fingerprint.

Cite this