Metabolism of inositol-1,3,4,6-tetrakisphosphate to inositol pentakisphosphate in adrenal glomerulosa cells.
Angiotensin II stimulates rapid formation of inositol-1,4,5-trisphosphate (Ins-1,4,5-P3) in bovine adrenal glomerulosa cells. In addition to being rapidly metabolized to lower inositol phosphates, Ins-1,4,5-P3 is converted to Ins-1,3,4,5-tetrakisphosphate (Ins-1,3,4,5-P4) and Ins-1,3,4-P3 which is in turn phosphorylated to a further Ins-P4 isomer, namely Ins-1,3,4,6-P4. In bovine adrenocortical cytosol [3H]Ins-1,3,4,5-P4 and [3H]Ins-1,3,4-P3 were converted to Ins-1,3,4,6-P4 and inositol pentakisphosphate (Ins-P5) in a metabolic sequence suggesting that unlike Ins-1,3,4,5-P4, Ins-1,3,4,6-P4 is a direct precursor of Ins-P5. Consistent with this assumption, [3H]Ins-1,3,4,6-P4 was converted to Ins-P5 in electropermeabilized adrenal glomerulosa cells. These findings demonstrate that Ins-1,3,4,6-P4 is an intermediate link between InsP3 metabolism and the higher inositol phosphates detected in several tissues.
Hunyady
L
L
Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Baukal
A J
AJ
Guillemette
G
G
Balla
T
T
Catt
K J
KJ
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000378:metabolism*; D007700:Kinetics; D010766:Phosphorylation; D013403:Sugar Phosphates / Q000378:metabolism*; D015384:Zona Glomerulosa / Q000378:metabolism*
D007295:Inositol Phosphates; D013403:Sugar Phosphates; C081655:inositol-1,3,4,5-tetrakisphosphate; C013571:inositol pentaphosphate; D015544:Inositol 1,4,5-Trisphosphate