Phosphoinositide synthesis in bovine rod outer segments

Journal Article · Tue Jun 12 00:00:00 EDT 1990 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00475a005· OSTI ID:5393710

Gehm, B D; McConnell, D G ^[1]

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1. Michigan State Univ., East Lansing (USA)

Phosphoinositide turnover has been implicated in signal transduction in a variety of cells, including photoreceptors. The authors demonstrate here the presence of a complete pathway for rapid synthesis of phosphoinositides in isolated bovine retinal rod outer segments (ROS) free of microsomal contaminants. Synthesis was measured by the incorporation of label from radioactive precursors, ({gamma}-{sup 32}P)ATP and ({sup 3}H)inositol. ({gamma}-{sup 32}P)ATP also produced large amounts of labeled phosphatidic acid. Incorporation of ({sup 3}H)inositol required CTP and Mn{sup 2+}. Mn{sup 2+} and Mg{sup 2+} increased {sup 32}P incorporation into phosphatidylinositol 4-phosphate, while spermine increased phosphoinositide labeling generally. ROS that had been washed to remove soluble and peripheral proteins incorporated less label than unwashed ROS into phosphatidic acid and phosphatidylinositol. No effects of light were detected. Inhibitory effects of high concentrations of nonhydrolyzable GTP analogues were probably due to competition with ATP.

• OSTI ID: 5393710
• Journal Information: Biochemistry; (United States), Vol. 29:23; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
PHOSPHOLIPIDS
BIOSYNTHESIS
RETINA
BIOLOGICAL PATHWAYS
ATP
CATIONS
CATTLE
INOSITOLS
MAGNESIUM COMPOUNDS
MANGANESE COMPOUNDS
MICROSOMES
PHOSPHORUS 32
TRITIUM COMPOUNDS
VISION
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
BODY AREAS
CARBOHYDRATES
CELL CONSTITUENTS
CHARGED PARTICLES
DAYS LIVING RADIOISOTOPES
DOMESTIC ANIMALS
ESTERS
EYES
FACE
HEAD
HYDROGEN COMPOUNDS
IONS
ISOTOPES
LIGHT NUCLEI
LIPIDS
MAMMALS
MONOSACCHARIDES
NUCLEI
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PHOSPHORUS ISOTOPES
RADIOISOTOPES
RIBOSOMES
RUMINANTS
SACCHARIDES
SENSE ORGANS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques