Linked Life Data

10419465

Source:http://linkedlifedata.com/resource/pubmed/id/10419465

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
31
pubmed:dateCreated
1999-8-19
pubmed:abstractText
One or more free hydroxyls of the phosphatidylinositol (PtdIns) head group undergo enzymatic phosphorylation, yielding phosphoinositides (PIs) with key functions in eukaryotic cellular regulation. Two such species, PtdIns 5-P and PtdIns 3,5-P(2), have now been identified in mammalian cells, but their biosynthesis remains unclear. We have isolated a novel mammalian PI kinase, p235, whose exact substrate specificity remained to be determined (Shisheva, A., Sbrissa, D., and Ikonomov, O. (1999) Mol. Cell. Biol. 19, 623-634). Here we report that recombinant p235 expressed in COS cells, like the authentic p235 in adipocytes, displays striking specificity for PtdIns over PI substrates and generates two products identified as PtdIns 5-P and PtdIns 3,5-P(2) by HPLC analyses. Synthetic PtdIns 3-P substrates were also converted to PtdIns 3,5-P(2) but to a substantially lesser extent than PtdIns isolated from natural sources. Important properties of the p235 PI 5-kinase include high sensitivity to nonionic detergents and relative resistance to wortmannin and adenosine. By analyzing deletion mutants in a heterologous cell system, we determined that in addition to the predicted catalytic domain other regions of the molecule are critical for the p235 enzymatic activity. HPLC resolution of monophosphoinositide products, generated by p235 immune complexes derived from lysates of 3T3-L1 adipocytes acutely stimulated with insulin, revealed essentially the same PtdIns 5-P levels as the corresponding p235 immune complexes of resting cells. However, the acute insulin action resulted in an increase of a wortmannin-sensitive PtdIns 3-P peak, suggestive of a plausible recruitment of wortmannin-sensitive PI 3-kinase(s) to p235. In conclusion, mouse p235 (renamed here PIKfyve) displays a strong in vitro activity for PtdIns 5-P and PtdIns 3,5-P(2) generation, implying PIKfyve has a key role in their biosynthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
21589-97
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:10419465-3T3 Cells, pubmed-meshheading:10419465-Adipocytes, pubmed-meshheading:10419465-Animals, pubmed-meshheading:10419465-COS Cells, pubmed-meshheading:10419465-Catalytic Domain, pubmed-meshheading:10419465-Chromatography, High Pressure Liquid, pubmed-meshheading:10419465-Fungal Proteins, pubmed-meshheading:10419465-Insulin, pubmed-meshheading:10419465-Mammals, pubmed-meshheading:10419465-Mice, pubmed-meshheading:10419465-Phosphatidylinositol 3-Kinases, pubmed-meshheading:10419465-Phosphatidylinositols, pubmed-meshheading:10419465-Phospholipids, pubmed-meshheading:10419465-Phosphotransferases (Alcohol Group Acceptor), pubmed-meshheading:10419465-Recombinant Proteins, pubmed-meshheading:10419465-Saccharomyces cerevisiae, pubmed-meshheading:10419465-Saccharomyces cerevisiae Proteins, pubmed-meshheading:10419465-Substrate Specificity, pubmed-meshheading:10419465-Transfection
pubmed:year
1999
pubmed:articleTitle
PIKfyve, a mammalian ortholog of yeast Fab1p lipid kinase, synthesizes 5-phosphoinositides. Effect of insulin.
pubmed:affiliation
Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't