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Inositol trisphosphatase and bisphosphatase activities in the retina of crab
Author(s) -
Trowell Stephen C.
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)80497-6
Subject(s) - inositol , second messenger system , inositol phosphate , transduction (biophysics) , visual phototransduction , biology , retina , inositol trisphosphate , chemistry , biochemistry , signal transduction , microbiology and biotechnology , biophysics , retinal , receptor , neuroscience
Inositol trisphosphate appears to be an excitatory second messenger in the transduction cascade of invertebrate visual photoreceptors. The high time‐resolution of visual transduction demands an efficient system for the removal of the second messenger. It is now demonstrated that soluble extracts of crab retina promote rapid magnesium‐dependent release of inorganic phosphate from D‐ myo ‐1,4,5,‐inositol trisphosphate. Experiments in which the inositol trisphosphate had been labelled with 32 P in the 4′ and 5′ positions indicated that both inositol trisphosphatase and bisphosphatase activities are present. The breakdown involves loss of at least one of the pair of vicinal phosphates, which is sufficient to inactivate the compound.