The dephosphorylation of inositol 1,4-bisphosphate to inositol in liver and brain involves two distinct Li+-sensitive enzymes and proceeds via inositol 4-phosphate.
1. Hydrolysis of both enantiomers of inositol 1-phosphate and both enantiomers of inositol 4-phosphate to inositol is inhibited by LiCl in liver and brain. 2. The phosphatase activity is predominantly soluble. 3. Inositol 1,4-bisphosphate is also hydrolysed by the soluble fraction of liver and brain. 4. Bisphosphatase activity is inhibited by LiCl, but is less sensitive than monophosphatase activity. 5. The product of bisphosphatase in liver and brain is inositol 4-phosphate.
Ragan
C I
CI
Department of Biochemistry, Merck Sharp and Dohme Research Laboratories, Harlow, Essex, U.K.
Watling
K J
KJ
Gee
N S
NS
Aspley
S
S
Jackson
R G
RG
Reid
G G
GG
Baker
R
R
Billington
D C
DC
Barnaby
R J
RJ
Leeson
P D
PD
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D002712:Chlorides / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D006868:Hydrolysis; D066298:In Vitro Techniques; D007294:Inositol / Q000378:metabolism; D007295:Inositol Phosphates / Q000378:metabolism*; D008094:Lithium / Q000494:pharmacology*; D018021:Lithium Chloride; D008099:Liver / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D051381:Rats; D013403:Sugar Phosphates / Q000378:metabolism*
D002712:Chlorides; D007295:Inositol Phosphates; D013403:Sugar Phosphates; C045537:inositol 4-phosphate; C044259:inositol 1,4-bis(phosphate); D007294:Inositol; D008094:Lithium; C054927:myo-inositol-4-phosphatase; D010744:Phosphoric Monoester Hydrolases; C021822:myo-inositol-1 (or 4)-monophosphatase; C053087:inositol-1,4-bisphosphate 1-phosphatase; D018021:Lithium Chloride