Transport of phosphocholine in higher plant cells: sup 31 P nuclear magnetic resonance studies

Journal Article · Fri Jun 01 00:00:00 EDT 1990 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.87.11.4280· OSTI ID:5392305

Gout, E; Bligny, R; Roby, C; Douce, R ^[1]

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1. Centre d'etudes Nucleaires de Grenoble et Universite Joseph Fourier (France)

Phosphocholine (PC) is an abundant primary form of organic phosphate that is transported in plant xylem sap. Addition of PC to the perfusate of compressed P{sub i}-starved sycamore cells monitored by {sup 31}P NMR spectroscopy resulted in an accumulation of PC and all the other phosphate esters in the cytoplasmic compartment. Addition of hemicholinium-3, an inhibitor of choline uptake, to the perfusate inhibited PC accumulation but not inorganic phosphate (P{sub i}). When the P{sub i}-starved cells were perfused with a medium containing either P{sub i} or PC, the resulting P{sub i} distribution in the cell was the same. Addition of choline instead of PC to the perfusate of compressed cells resulted in an accumulation of PC in the cytoplasmic compartment from choline kinase activity. In addition, PC phosphatase activity has been discovered associated with the cell wall. These results indicate that PC was rapidly hydrolyzed outside the cell and that choline and P{sub i} entered the cytosolic compartment where choline kinase re-forms PC.

• OSTI ID: 5392305
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Vol. 87:11; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
CHOLINE
NUCLEAR MAGNETIC RESONANCE
PLANT CELLS
MEMBRANE TRANSPORT
CELL WALL
ENZYME ACTIVITY
PHOSPHATASES
PHOSPHONIC ACID ESTERS
PHOSPHORUS 31
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
CELL CONSTITUENTS
DRUGS
ENZYMES
ESTERASES
ESTERS
HYDROLASES
HYDROXY COMPOUNDS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
QUATERNARY COMPOUNDS
RESONANCE
STABLE ISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics