The presence of sn-1-palmitoyl lysophosphatidylinositol monophosphate correlates positively with the fusion-permissive state of the plasma membrane of fusogenic carrot cells grown in suspension culture

Wheeler, Jeffery J.; Boss, Wendy F.

doi:10.1016/0005-2736(89)90339-8

Cited by 11 publications

(4 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When LPI was used as a substrate, it was reconstituted in CH,CI:MeOH (1:2). Aliquots of 20 pL (from a 1 mg/mL stock of LPI) were placed in test tubes and dried under nitrogen as described by Wheeler and Boss (1989). When the effects of cations were tested, MgC1, or MnCI, were added at the concentrations indicated; calcium was added as CaCIJEGTA to give the free calcium concentrations indicated as described by Buckhout (1984).…”

Section: Enzyme Assaymentioning

confidence: 99%

Purification and Characterization of a Soluble Phosphatidylinositol 4-Kinase from Carrot Suspension Culture Cells

et al. 1995

View full text Add to dashboard Cite

Previously we reported the presence of a soluble phosphatidylinositol 4-kinase (PI 4-kinase) in carrot (Daucus carofa L.) suspension culture cells (C.M. Okpodu, W. Cross, W.F. Boss 119901 Plant Physiol 93: S-63). We have purified the enzyme over 1000-fold using Q-Sepharose ion exchange, hydroxylapatite, and G-1 O0 gel filtration column chromatography. The M, of the enzyme was estimated to be 83,000 by gel filtration. PI 4-kinase activity was recovered after renaturation of the 80-kD region of polyacrylamide gels, and an 80-kD peptide cross-reacted with antibodies to the yeast 55-kD membrane-associated PI 4-kinase on western blots. l h e isolated lipid kinase phosphorylated PI but not lysophosphatidylinosito1 or phosphatidylinositol monophosphate. Maximal PI kinase activity occurred when the substrate was added as Triton X-lOO/PI mixed micelles at pH 8. The enzyme required divalent cations. At low concentrations (1-5 mM), Mn2+ was more effective than Mgz+ in increasing enzyme activity; however, maximal activity occurred at 25 to 40 mM Mgz+. Calcium from 0.01 p~ to 1 mM had no effect on the enzyme activity. The K,,, of the enzyme for ATP was estimated to be between 400 and 463 p~. The enzyme was inhibited by adenosine (100 p~) ; however, ADP (up to 100 p~) had no effect on the activity. The biochemical characteristics of the carrot soluble PI 4-kinase are compared with the previously reported PI 4-kinases from animals and yeast.

show abstract

Section: Enzyme Assaymentioning

confidence: 99%

Purification and Characterization of a Soluble Phosphatidylinositol 4-Kinase from Carrot Suspension Culture Cells

et al. 1995

View full text Add to dashboard Cite

show abstract

“…Andr6 (1989, 1993) demonstrated that auxins rapidly stimulate PLA2 in soybean cells in culture. Wheeler and Boss (1989) demonstrated that the presence of sn-l-palmitoyl lysophosphatidylinositol monophosphate (an indirect measurement of PLA2 activity) correlates positively with the fusion capacity of protoplasts.…”

Section: Phospholipids and Phospholipid Metabolites As Mediators Of Cellular Signaling And Cytoskeletal Reorganizationmentioning

confidence: 99%

Lipids trigger changes in the elasticity of the cytoskeleton in plant cells: a cell optical displacement assay for live cell measurements.

Grabski

Xie

Holland

et al. 1994

The Journal of Cell Biology

View full text Add to dashboard Cite

Abstract. An assay has been developed to quantitatively measure the tension and elasticity of the cytoskeleton in living plant cells. The cell optical displacement assay (CODA) uses a focused laser beam to optically trap and displace transvacuolar and cortical strands through a defined distance within the cell. Results from these experiments provide evidence for the classification of at least two rheologically distinct cytoskeletal assemblies, cortical and transvacuolar, that differ in their tension and response to both signaling molecules and reagents that perturb the cytoskeleton. It is further demonstrated that the tension of the transvacuolar strands can be significantly decreased by the addition of either linoleic acid, 1,2 dioctanoylsn-glycerol, or 1,3 dioctanoylglycerol. These decreases in tension could also be induced by lowering the cytoplasmic pH. In contrast, addition of Ca 2+, Mg 2+, or the ionophore A23187 to the cells caused a considerable increase in the tension of the transvacuolar strands. The data provides evidence that: (a) linoleic acid may be a signaling molecule in plant cells; (b) diacylglycerol functions as a signaling molecule through a protein kinase C-independent pathway mediated by PLA2; and (c) Ca 2+ and pH have regulatory roles for controlling cytoskeleton tension and organization.

show abstract

“…Lysophosphoinositides. Wheeler & Boss (1989) showed that significant amounts of lysophosphoinositides are present in plant cells. Little is currently known about their function, but it has been suggested that they may be involved in processes as diverse as secretion, fertilization, protoplast fusion and regulation of enzyme activity (Wheeler & Boss, 1990).…”

Section: Inositol(145)p3 and Ca2+ Releasementioning

confidence: 99%

The plant phosphoinositide system

Drøbak

1992

Biochemical Journal

157

121

View full text Add to dashboard Cite

show abstract

The presence of sn-1-palmitoyl lysophosphatidylinositol monophosphate correlates positively with the fusion-permissive state of the plasma membrane of fusogenic carrot cells grown in suspension culture

Cited by 11 publications

References 23 publications

Purification and Characterization of a Soluble Phosphatidylinositol 4-Kinase from Carrot Suspension Culture Cells

Purification and Characterization of a Soluble Phosphatidylinositol 4-Kinase from Carrot Suspension Culture Cells

Lipids trigger changes in the elasticity of the cytoskeleton in plant cells: a cell optical displacement assay for live cell measurements.

The plant phosphoinositide system

Contact Info

Product

Resources

About