Molecular evolution of the lysophosphatidic acid acyltransferase (LPAAT) gene family

Abstract

Lysophosphatidic acid acyltransferases (LPAATs) perform an essential cellular function by controlling the production of phosphatidic acid (PA), a key intermediate in the synthesis of membrane, signaling and storage lipids. Although LPAATs have been extensively explored by functional and biotechnological studies, little is known about their molecular evolution and diversification. We performed a genome-wide analysis using data from several plants and animals, as well as other eukaryotic and prokaryotic species, to identify LPAAT genes and analyze their evolutionary history. We used phylogenetic and molecular evolution analysis to test the hypothesis of distinct origins for these genes. The reconstructed phylogeny supported the ancient origin of some isoforms (plant LPAAT1 and LPAATB; animal AGPAAT1/2), while others emerged more recently (plant LPAAT2/3/4/5; AGPAAT3/4/5/8). Additionally, the hypothesis of endosymbiotic origin of the plastidic isoform LPAAT1 was confirmed. LPAAT genes from plants and animals mainly experienced strong purifying selection pressures with limited functional divergence after the species-specific duplications. Gene expression analyses of LPAAT isoforms in model plants demonstrated distinct LPAAT expression patterns in these organisms. The results showed that distinct origins followed by diversification of the LPAAT genes shaped the evolution of TAG biosynthesis. The expression pattern of individual genes may be responsible for adaptation into multiple ecological niches.

Occurrence of plastidial triacylglycerol synthesis and the potential regulatory role of AGPAT in the model diatom Phaeodactylum tricornutum

“…It is well known that AGPAT1 plays a significant role in producing phosphatidic acid (PA), a key fatty acid component in the synthesis of plastidial membrane, lipids etc. [3, 28]. Thus, the key role of providing fatty acid components by AGPAT1 resulted in elevated photosynthetic activity, which is in accordance with the previous reports.

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Diversity and evolution of plant diacylglycerol acyltransferase (DGATs) unveiled by phylogenetic, gene structure and expression analyses

“…This demonstrates that duplication events were important for the evolution and diversification of these genes. Gene duplication has also driven the evolution and diversification of LPAAT members during plant evolution (Korbes et al , 2016). This gene encodes a soluble protein that belongs to the BAHD family (Rani et al , 2010).…”

“…Subsequently, PA is dephosphorylated to generate diacylglycerol (DAG), which is converted to TAG through the action of acylCoA:diacylglycerol acyltransferase (DGAT; EC 3.2.1.20) (Kenedy and Weiss, 1956; Ohlrogge and Browse, 1995). Some studies about evolutionary history of Kennedy pathway enzymes were performed in the last years (Turchetto-Zolet et al , 2011; Smart et al , 2014, Korbes et al , 2016). DGAT is considered a key enzyme in the conversion of DAG to TAG and therefore has been proposed as the rate-limiting enzyme in plant storage lipid accumulation (Ichihara et al.…”

PIECE 2.0: an update for the plant gene structure comparison and evolution database

“…Users can easily integrate, visualize and analyze phylogenetic trees, intron–exon structure, protein domains and intron phase. PIECE has been widely used by plant biologists for functional and evolutionary studies of gene families and orthologs (24–29). Here, we reported the new PIECE 2.0 version with updated gene structure data sets by including 24 newly sequenced genomes since the release of PIECE 1.0 and with a significant improvement of the view function to display phylogenetic trees along with gene structure and protein domains.…”