title: The Arabidopsis ABHD11 Mutant Accumulates Polar Lipids in Leaves as a Consequence of Absent Acylhydrolase Activity.
abstract: Alpha/beta hydrolase domain (ABHD)-containing proteins are structurally related with diverse catalytic activities. In various species, some ABHD proteins have been characterized and shown to play roles in lipid homeostasis. However, little is known about ABHD proteins in plants. Here, we characterized AT4G10030 (AtABHD11), an Arabidopsis (Arabidopsis thaliana) homolog of a human ABHD11 gene. In silico analyses of AtABHD11 revealed homology with other plant species with a conserved GXSXG lipid motif. Interestingly, Arabidopsis abhd11 mutant plants exhibited an enhanced growth rate compared with wild-type plants. Quantitative analyses of the total lipids showed that the mutant abhd11 has a high amount of phospholipid and galactolipid in Arabidopsis leaves. The overexpression of AtABHD11 in Escherichia coli led to a reduction in phospholipid levels. The bacterially expressed recombinant AtABHD11 hydrolyzed lyso(phospho)lipid and monoacylglycerol. Furthermore, using whole-genome microarray and real-time PCR analyses of abhd11 and wild-type plants, we noted the up-regulation of MGD1, -2, and -3 and DGD1. Together, these findings suggested that AtABHD11 is a lyso(phospho)lipase. The disruption of AtABHD11 caused the accumulation of the polar lipids in leaves, which in turn promoted a higher growth rate compared with wild-type plants.
authors.affiliation: Lipidomics Centre, Department of Lipid Science (A.V., P.V., R.R.), and Fruit and Vegetable Technology Department (A.K.V.), Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research-Central Food Technological Research Institute, Mysore 570020, India.
authors.forename: Anitha
authors.initials: A
authors.lastname: Vijayakumar
authors.affiliation: Lipidomics Centre, Department of Lipid Science (A.V., P.V., R.R.), and Fruit and Vegetable Technology Department (A.K.V.), Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research-Central Food Technological Research Institute, Mysore 570020, India.
authors.forename: Panneerselvam
authors.initials: P
authors.lastname: Vijayaraj
authors.affiliation: Lipidomics Centre, Department of Lipid Science (A.V., P.V., R.R.), and Fruit and Vegetable Technology Department (A.K.V.), Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research-Central Food Technological Research Institute, Mysore 570020, India.
authors.forename: Arun Kumar
authors.initials: AK
authors.lastname: Vijayakumar
authors.affiliation: Lipidomics Centre, Department of Lipid Science (A.V., P.V., R.R.), and Fruit and Vegetable Technology Department (A.K.V.), Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research-Central Food Technological Research Institute, Mysore 570020, India ram@cftri.com.
authors.forename: Ram
authors.initials: R
authors.lastname: Rajasekharan
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D006720:Homozygote; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism; D050356:Lipid Metabolism / Q000235:genetics*; D008055:Lipids / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010743:Phospholipids / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015854:Up-Regulation
chemical_list: D029681:Arabidopsis Proteins; D008055:Lipids; D010743:Phospholipids; D011994:Recombinant Proteins; C000610952:ABHD11 protein, Arabidopsis; D006867:Hydrolases