Molecular cloning and characterization of MACIF, an inhibitor of membrane channel formation of complement.
Human erythrocytes contain a membrane protein, MACIF, which inhibits the formation of a membrane attack complex (MAC) of complement. We have cloned and sequenced the complementary DNA of MACIF messenger RNA. The amino acid sequence predicted from its nucleotide sequence consists of 128 amino acids. The amino-terminal 25 residues may correspond to a signal peptide. The carboxy-terminal sequence confirmed that MACIF is a glycosylphosphatidylinositol (GPI)-anchored protein. The amino acid sequence of MACIF was partially determined by established techniques for protein chemistry and the resultant sequence was consistent with that predicted from the nucleotide sequence. The results of sequence analyses also suggested that asparagine at the 18th position was N-glycosylated. When mRNA obtained from the MACIF cDNA clone with SP6 RNA polymerase was microinjected into Xenopus oocytes, the oocytes synthesized a product which exhibited MACIF activity and reacted with anti-MACIF antibody. Comparison of the predicted sequence revealed significant homology with mouse Ly-6 antigens.
Sugita
Y
Y
School of Pharmaceutical Sciences, Showa University, Tokyo.
Tobe
T
T
Oda
E
E
Tomita
M
M
Yasukawa
K
K
Yamaji
N
N
Takemoto
T
T
Furuichi
K
K
Takayama
M
M
Yano
S
S
D000595:Amino Acid Sequence; D000818:Animals; D000950:Antigens, Ly / Q000235:genetics; D001483:Base Sequence; D001798:Blood Proteins / Q000032:analysis / Q000235:genetics*; D018957:CD59 Antigens; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D015938:Complement Membrane Attack Complex / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D004247:DNA / Q000032:analysis; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis; D012689:Sequence Homology, Nucleic Acid; D014357:Trypsin
D000950:Antigens, Ly; D001798:Blood Proteins; D018957:CD59 Antigens; D015938:Complement Membrane Attack Complex; D010455:Peptides; D004247:DNA; D014357:Trypsin