THE DIVERSITY OF ALGAE PHOSPHOLIPASE D HOMOLOGS REVEALED BY BIOCOMPUTATIONAL ANALYSIS

MARIA VERONICA BELIGNI; MARÍA BELÉN PRADOS; CAROLINA BAGNATO; HERNÁN BONDINO; ANA MARÍA LAXALT; TEUN MUNNIK; 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 the formation of phosphatidic acid, a precursor inglycerolipid biosynthesis and a second messenger. PLDs are part of a superfamily of proteins thathydrolyze phosphodiesters and share a catalytic motif, HxKxxxxD, and hence a mechanism ofaction. Although HKD-PLDs have been thoroughly characterized in plants, animals and bacteria,very little is known about these enzymes in algae. To fill this gap in knowledge, we performed abiocomputational analysis by means of HMMER iterative profiling, using most algae genomesavailable. Phylogenetic analysis revealed that algae exhibit very few eukayotic-type PLDs butpossess, instead, many bacteria-like PLDs. Among algae canonical eukaryotic PLDs, we identifiedC2-PLDs and PXPH-like PLDs. In addition, the dinoflagellate Alexandrium tamarense featuresseveral proteins phylogenetically related to oomycete PLDs. The bacteria-like HKD superfamilyincludes 5 clades of bacteria-like PLDs (proteins with putative PLD activity). Clade I is almostexclusive to diatoms, whereas Clade II and IV are mainly represented by proteins fromprasinophytes. These three clades likely constitute novel PLD subfamilies. The other two clades arecomposed of mitochondrial PLDs (Clade V or Mito-PLDs), previously found in mammals, and asubfamily of potentially secreted proteins (Clade III or SP-PLDs), which includes a homologformerly characterized in rice. In addition, the bacteria-like HKD superfamily includes non-PLDmembers with putative cardiolipin synthase and phosphatidylserine/phosphatidylglycerophosphatesynthase activities. Altogether, our results show that algae possess several divergent types of PLDs, probably originated from a number of ancestors, often, but not always, explained by theirtaxonomic relationships.