The diversity of algae phospholipase d homologs revealed by biocomputational analysis

BELIGNI, MV; BAGNATO, C; PRADOS MB; BONDINO HG; LAXALT AM; MUNNIK T; ARJEN TEN HAVE

JOURNAL OF PHYCOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2015 vol. 51 p. 943 - 962

0022-3646

Phospholipase D (PLD) participates in theformation of phosphatidic acid, a precursor inglycerolipid biosynthesis and a second messenger.PLDs are part of a superfamily of proteins thathydrolyze phosphodiesters and share a catalyticmotif, HxKxxxxD, and hence a mechanism ofaction. Although HKD-PLDs have been thoroughlycharacterized in plants, animals and bacteria, verylittle is known about these enzymes in algae. To fillthis gap in knowledge, we performed abiocomputational analysis by means of HMMERiterative profiling, using most eukaryotic algaegenomes available. Phylogenetic analysis revealedthat algae exhibit very few eukaryotic-type PLDs butpossess, instead, many bacteria-like PLDs. Amongalgae eukaryotic-type PLDs, we identified C2-PLDsand PXPH-like PLDs. In addition, the dinoflagellateAlexandrium tamarense features several proteinsphylogenetically related to oomycete PLDs. Ourphylogenetic analysis also showed that algae bacteria-like PLDs (proteins with putative PLDactivity) fall into five clades, three of which arenovel lineages in eukaryotes, composed almostentirely of algae. Specifically, Clade II is almostexclusive to diatoms, whereas Clade I and IV aremainly represented by proteins from prasinophytes.The other two clades are composed ofmitochondrial PLDs (Clade V or Mito-PLDs),previously found in mammals, and a subfamily ofpotentially secreted proteins (Clade III or SP-PLDs),which includes a homolog formerly characterized inrice. In addition, our phylogenetic analysis showsthat algae have non-PLD members within thebacteria-like HKD superfamily with putativecardiolipin synthaseandphosphatidylserine/phosphatidylglycerophosphate synthase activities.Altogether, our results show that eukaryotic algaepossess a moderate number of PLDs that belong tovery diverse phylogenetic groups.