Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02749 (beta2-glycoprotein I)
 836 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

cDNAs encoding the complement decay-accelerating factor (DAF) were isolated from HeLa and differentiated HL-60 lambda gt 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 approximately equal to 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 beta 2-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.
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PMID:Cloning and characterization of cDNAs encoding the complete sequence of decay-accelerating factor of human complement. 243 22

By using synthetic oligonucleotides as probes, plasmid clones containing portions of cDNA coding for human C4b-binding protein were isolated from a liver cDNA library. The entire amino acid sequence of the C4b-binding protein can be predicted from this study of the cloned cDNA when allied to a previous sequence study at the protein level [Chung, Gagnon & Reid (1985) Mol. Immunol. 22, 427-435], in which over 55% of the amino acid sequence, including the N-terminal 62 residues, was obtained. The plasmid clones isolated allowed the unambiguous determination of 1717 nucleotides of cDNA sequence between the codon for the 32nd amino acid in the sequence of C4b-binding protein and the 164th nucleotide in the 3' non-translated region. The sequence studies show that the secreted form of C4b-binding protein, found in plasma, is composed of chains of apparent Mr 70 000 that contains 549 amino acid residues. Examination of the protein and cDNA sequence results show that there are at least two polymorphic sites in the molecule. One is at position 44, which can be glutamine or threonine, and the other is at position 309, which can be tyrosine or histidine. Northern-blot analysis indicated that the mRNA for C4b-binding protein is approx. 2.5 kilobases long. The N-terminal 491 amino acids of C4b-binding protein can be divided into eight internal homologous regions, each approx. 60 amino acids long, which can be aligned by the presence in each region of four half-cystine, one tryptophan and several other conserved residues. These regions in C4b-binding protein are homologous with the three internal-homology regions that have been reported to be present within the Ba region of the complement enzyme factor B and also to the internal-homology regions found in the non-complement beta 2-glycoprotein I.
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PMID:Molecular cloning and characterization of the cDNA coding for C4b-binding protein, a regulatory protein of the classical pathway of the human complement system. 384 Mar 70