Cyclin-dependent kinase activity enhances phosphatidylcholine biosynthesis in Arabidopsis by repressing phosphatidic acid phosphohydrolase activity.
Coordination of endomembrane biogenesis with cell cycle progression is considered to be important in maintaining cell function during growth and development. We previously showed that the disruption of PHOSPHATIDIC ACID PHOSPHOHYDROLASE (PAH) activity in Arabidopsis thaliana stimulates biosynthesis of the major phospholipid phosphatidylcholine (PC) and causes expansion of the endoplasmic reticulum. Here we show that PC biosynthesis is repressed by disruption of the core cell cycle regulator CYCLIN-DEPENDENT KINASE A;1 (CDKA;1) and that this repression is reliant on PAH. Furthermore, we show that cyclin-dependent kinases (CDKs) phosphorylate PAH1 at serine 162, which reduces both its activity and membrane association. Expression of a CDK-insensitive version of PAH1 with a serine 162 to alanine substitution represses PC biosynthesis and also reduces the rate of cell division in early leaf development. Together our findings reveal a physiologically important mechanism that couples the rate of phospholipid biosynthesis and endomembrane biogenesis to cell cycle progression in Arabidopsis.
School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
Christian P
CP
Craddock
School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
Nicolette
N
Adams
School of Biological and Biomedical Sciences, Durham University, Durham, DH1 3LE, UK.
Johan T M
JT
Kroon
Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
Fiona M
FM
Bryant
School of Biological and Biomedical Sciences, Durham University, Durham, DH1 3LE, UK.
Patrick J
PJ
Hussey
Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
Smita
S
Kurup
Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Hertfordshire, AL5 2JQ, UK.
Peter J
PJ
Eastmond
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002453:Cell Cycle / Q000235:genetics; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010711:Phosphatidate Phosphatase / Q000235:genetics / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D010766:Phosphorylation; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D030821:Plants, Genetically Modified
D029681:Arabidopsis Proteins; D007527:Isoenzymes; D010713:Phosphatidylcholines; C434472:CDKA1 protein, Arabidopsis; D018844:Cyclin-Dependent Kinases; D010711:Phosphatidate Phosphatase

Arabidopsis thaliana
; cell cycle; cyclin-dependent kinase; membrane biogenesis; phosphatidic acid phosphohydrolase; phosphatidylcholine; phospholipid biosynthesis; phosphorylation