Molecular characterization of cytosolic phospholipase A2-beta.
We have isolated a cDNA encoding a 1012-amino acid polypeptide cPLA2-beta, that has significant homology with cPLA2-alpha in both the calcium-dependent lipid binding domain as well as in the catalytic domain. Transient expression of cPLA2-beta cDNA in COS cells results in an increase in calcium-dependent phospholipase A1 (PLA1) and PLA2 activities compared with vector-transfected cells. cPLA2-beta is markedly less selective for cleavage at sn-2 as compared with cPLA2-alpha and cPLA2-gamma. Northern analysis reveals a cPLA2-beta transcript of 8 kilobase pairs that is expressed in all the human tissues examined. With the identification of cPLA2-beta, the newly defined cPLA2 family now comprises three members that may have dramatically different mechanisms for regulation of expression and enzymatic activation.
Song
C
C
Small Molecule Drug Discovery Group, Genetics Institute, Cambridge, Massachusetts 02140, USA.
Chang
X J
XJ
Bean
K M
KM
Proia
M S
MS
Knopf
J L
JL
Kriz
R W
RW
D000595:Amino Acid Sequence; D002118:Calcium / Q000494:pharmacology; D003001:Cloning, Molecular; D003600:Cytosol / Q000201:enzymology*; D018076:DNA, Complementary / Q000235:genetics; D015723:Gene Library; D054513:Group IV Phospholipases A2; D006801:Humans; D008969:Molecular Sequence Data; D010741:Phospholipases A / Q000096:biosynthesis / Q000187:drug effects / Q000235:genetics*; D054466:Phospholipases A1; D054467:Phospholipases A2; D011994:Recombinant Proteins / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D020298:U937 Cells
D018076:DNA, Complementary; D011994:Recombinant Proteins; D010741:Phospholipases A; D054466:Phospholipases A1; D054513:Group IV Phospholipases A2; D054467:Phospholipases A2; D002118:Calcium