MAMMALIAN LOW MOLECULAR WEIGHT PHOSPHOLIPASE A2 NUCLEOTIDE AND AMINO ACID SEQUENCES

摘要

Novel mammalian phospholipase (PLA2) nucleotide sequences and low molecular weight (about 14 KD) amino acid sequences encoded thereby are disclosed. More particularly, a cloned human HPLA2 cDNA expressing HPLA2-10 and its cloned rat RPLA2 cDNA counterpart, expressing RPLA2-10, which are characterized as PLA2 Type IV, are disclosed. A second type of PLA2 cDNA, characterized as PLA2 Type III and exemplified by a rat PLA2 cDNA encoding RPLA2-8 and a partial human PLA2 nucleotide sequence encoding HPLA2-8, is disclosed. Expression of the cDNAs encode the two new types of PLA2 enzymes which have phospholipase activity. The novel PLA2s do not include disulfide bridges between cysteine amino acids 11 and 77 or elapid loops. However, the novel PLA2s may include amino acid COOH-terminal extensions which can vary in length. Seventeen of the eighteen absolutely conserved amino acids in all active 14 KD PLA2s are believed to be conserved in RPLA2-8 and HPLA2-8, whereas all eighteen are believed to be conserved in RPLA2-10 and HPLA2-10. Because the encoded sequences of RPLA2-8 and HPLA2-8 include only 16 cysteine amino acids, they have been designated as Type III. RPLA2-10 and HPLA2-10 are designated as Type IV since their encoded sequences include only 12 cysteine amino acids.