Linked Life Data

1677198

Source:http://linkedlifedata.com/resource/pubmed/id/1677198

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1309
pubmed:dateCreated
1991-8-16
pubmed:abstractText
The localization of the human erythrocyte membrane Ins(1,3,4,5)P4 3-phosphatase was investigated by saponin permeabilization of resealed 'isoionic' erythrocyte ghosts. This enzyme is active at the inner face of the plasma membrane, at the same site as a specific 5-phosphatase that degrades both Ins (1,4,5)P3 and Ins(1,3,4,5)P4. In the presence of EDTA, Ins(1,4,5)P3 was the only product of Ins(1,3,4,5)P4 metabolism. However, when Mg2+ was present both the 5-phosphatase and the 3-phosphatase attacked Ins (1,3,4,5)P4, directly forming Ins(1,3,4)P3 and Ins(1,4,5)P3;some Ins(1,4)P2 was also formed as a product of 5-phosphatase attack on the liberated Ins(1,4,5)P3. The Ins(1,3,4,5)P4 3-phosphatase was potently activated by KCl, thus making the route of metabolism of Ins(1,3,4,5)P4 by erythrocyte ghosts strikingly sensitive to variations in ionic strength: at 'cytosolic' K+ and Mg2+ levels, 3-phosphatase activity slightly predominated over 5-phosphatase. Ins(1,3,4,5)P4 3-phosphatase was potently inhibited by Ins-(1,3,4,5,6)P5 and InsP6 at levels lower than those often observed within cells. This leaves open the question as to whether the cellular function of inositol polyphosphate 3-phosphatase is to participate in a physiological cycle that interconverts Ins(1,3,4,5)P4 and Ins(1,4,5)P3 or to metabolize other inositol polyphosphates in the cytosol compartment of cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0962-8452
pubmed:author
pubmed:issnType
Print
pubmed:day
22
pubmed:volume
244
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
63-8
pubmed:dateRevised
2007-9-7
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
A salt-activated inositol 1,3,4,5-tetrakisphosphate 3-phosphatase at the inner surface of the human erythrocyte membrane.
pubmed:affiliation
School of Biochemistry, University of Birmingham, U.K.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't