Inositol trisphosphate metabolism in carrot (Daucus carota L. ) cells

Journal Article · Sun Oct 01 00:00:00 EDT 1989 · Plant Physiology; (USA)

DOI:https://doi.org/10.1104/pp.91.2.477· OSTI ID:5922786

Memon, A R; Rincon, M; Boss, W F ^[1]

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1. North Carolina State Univ., Raleigh (USA)

The metabolism of exogenously added D-myo-(1-{sup 3}H)inositol 1,4,5-trisphosphate (IP{sub 3}) has been examined in microsomal membrane and soluble fractions of carrot cells grown in suspension culture. When ({sup 3}H)IP{sub 3} was added to a microsomal membrane fraction, ({sup 3}H)IP{sub 2} was the primary metabolite consisting of approximately 83% of the total recovered ({sup 3}H) by electrophoresis. ({sup 3}H)IP was only 6% of the ({sup 3}H) recovered, and 10% of the ({sup 3}H)IP{sub 3} was not further metabolized. In contrast, when ({sup 3}H)IP{sub 3} was added to the soluble fraction, approximately equal amounts of ({sup 3}H)IP{sub 2} and ({sup 3}H)IP were recovered. Ca{sup 2+} (100 micromolar) tended to enhance IP{sub 3} dephosphorylation but inhibited the IP{sub 2} dephosphorylation in the soluble fraction by about 20%. MoO{sub 4}{sup 2{minus}} (1 millimolar) inhibited the dephosphorylation of IP{sub 3} by the microsomal fraction and the dephosphorylation of IP{sub 2} by the soluble fraction. MoO{sub 4}{sup 2{minus}}, however, did not inhibit the dephosphorylation of IP{sub 3} by the soluble fraction. Li{sup +} (10 and 50 millimolar) had no effect on IP{sub 3} metabolism in either the soluble or membrane fraction; however, Li{sup +} (50 millimolar) inhibited IP{sub 2} dephosphorylation in the soluble fraction about 25%.

• OSTI ID: 5922786
• Journal Information: Plant Physiology; (USA), Journal Name: Plant Physiology; (USA) Vol. 91:2; ISSN 0032-0889; ISSN PLPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
CARBOHYDRATES
CARROTS
CELL CONSTITUENTS
FOOD
HYDROGEN COMPOUNDS
INOSITOL
INOSITOLS
ISOTOPE APPLICATIONS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
MEMBRANES
METABOLISM
MICROSOMES
MONOSACCHARIDES
ORGANIC COMPOUNDS
ORGANOIDS
PLANTS
RIBOSOMES
SACCHARIDES
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VEGETABLES