Loss of plastidic lysophosphatidic acid acyltransferase causes embryo-lethality in Arabidopsis.
Phosphatidic acid is a key intermediate for chloroplast membrane lipid biosynthesis. De novo phosphatidic acid biosynthesis in plants occurs in two steps: first the acylation of the sn-1 position of glycerol-3-phosphate giving rise to lysophosphatidic acid; second, the acylation of the sn-2 position of lysophosphatidic acid to form phosphatidic acid. The second step is catalyzed by a lysophosphatidic acid acyltransferase (LPAAT). Here we describe the identification of the ATS2 gene of Arabidopsis encoding the plastidic isoform of this enzyme. Introduction of the ATS2 cDNA into E. coli JC 201, which is temperature-sensitive and carries a mutation in its LPAAT gene plsC, restored this mutant to nearly wild type growth at high temperature. A green-fluorescent protein fusion with ATS2 localized to the chloroplast. Disruption of the ATS2 gene of Arabidopsis by T-DNA insertion caused embryo lethality. The development of the embryos was arrested at the globular stage concomitant with a transient increase in ATS2 gene expression. Apparently, plastidic LPAAT is essential for embryo development in Arabidopsis during the transition from the globular to the heart stage when chloroplasts begin to form.
Yu
Bin
B
Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824-1319, USA.
Wakao
Setsuko
S
Fan
Jilian
J
Benning
Christoph
C
D000217:Acyltransferases / Q000172:deficiency* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017360:Arabidopsis / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D002736:Chloroplasts / Q000201:enzymology / Q000235:genetics; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D005227:Fatty Acids / Q000096:biosynthesis; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D018390:Gene Targeting; D005804:Genes, Lethal / Q000235:genetics; D050356:Lipid Metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010712:Phosphatidic Acids / Q000096:biosynthesis; D010802:Phylogeny; D018087:Plastids / Q000201:enzymology* / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D012639:Seeds / Q000196:embryology / Q000201:enzymology* / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013696:Temperature; D020524:Thylakoids / Q000378:metabolism
D018076:DNA, Complementary; D005227:Fatty Acids; D010712:Phosphatidic Acids; D020033:Protein Isoforms; D000217:Acyltransferases; C018764:2-acylglycerophosphate acyltransferase