The Arabidopsis phospholipase D family. Characterization of a calcium-independent and phosphatidylcholine-selective PLD zeta 1 with distinct regulatory domains.
Four types of phospholipase D (PLD), PLD alpha, beta, gamma, and delta, have been characterized in Arabidopsis, and they display different requirements for Ca(2+), phosphatidylinositol 4,5-bisphosphate (PIP(2)), substrate vesicle composition, and/or free fatty acids. However, all previously cloned plant PLDs contain a Ca(2+)-dependent phospholipid-binding C2 domain and require Ca(2+) for activity. This study documents a new type of PLD, PLD zeta 1, which is distinctively different from previously characterized PLDs. It contains at the N terminus a Phox homology domain and a pleckstrin homology domain, but not the C2 domain. A full-length cDNA for Arabidopsis PLD zeta 1 has been identified and used to express catalytically active PLD in Escherichia coli. PLD zeta 1 does not require Ca(2+) or any other divalent cation for activity. In addition, it selectively hydrolyzes phosphatidylcholine, whereas the other Arabidopsis PLDs use several phospholipids as substrates. PLD zeta 1 requires PIP(2) for activity, but unlike the PIP(2)-requiring PLD beta or gamma, phosphatidylethanolamine is not needed in substrate vesicles. These differences are described, together with a genomic analysis of 12 putative Arabidopsis PLD genes that are grouped into alpha, beta, delta, gamma, and zeta based on their gene architectures, sequence similarities, domain structures, and biochemical properties.
Qin
Chunbo
C
Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506, USA.
Wang
Xuemin
X
D020816:Amino Acid Motifs / Q000235:genetics; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002874:Chromosome Mapping; D004926:Escherichia coli; D015870:Gene Expression; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D010712:Phosphatidic Acids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism*; D010739:Phospholipase D / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
D029681:Arabidopsis Proteins; D007527:Isoenzymes; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines; D010739:Phospholipase D; D002118:Calcium