Linked Life Data

2537212

Source:http://linkedlifedata.com/resource/pubmed/id/2537212

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1989-4-3
pubmed:abstractText
Rabbit fast-twitch skeletal muscle microsomes have been separated by isopycnic centrifugation on a linear sucrose gradient into triads and light sarcoplasmic reticulum. In both fractions phosphatidylinositol-kinase activity is found [Varsányi et al. (1986) Biochem. Biophys. Res. Commun. 138, 1395]. In contrast, phosphatidylinositol-4-phosphate kinase is nearly exclusively associated with triads. The phosphatidylinositol-4,5-bisphosphate-phosphodiesterase activity shows a biphasic distribution: approximately 50% of the activity is associated with triads and 50% appears in the overlay. Triads have been broken mechanically into transverse tubules and terminal cisternae, then separated by isopycnic sucrose-gradient centrifugation. Both fractions exhibit phosphatidylinositol-kinase activity; the activities of phosphatidylinositol-4-phosphate kinase and phosphatidylinositol-4,5-bisphosphate phosphodiesterase are associated mainly with the transverse tubules. Consequently, in rabbit fast-twitch skeletal muscle all necessary enzymes for production of D-myo-inositol 1,4,5-trisphosphate are associated with transverse tubules. Phosphatidylinositol-4,5-bisphosphate phosphodiesterase associated with triads shows a pH optimum at 6.8. The enzyme is maximally active between pCa 5 and pCa 4. Mg2+ inhibits the enzyme activity half-maximally at about 1 mM. Guanine-nucleotide-binding proteins seem not to be involved in the regulation of enzyme activity; guanosine 5'-[gamma-thio]triphosphate does not influence phosphatidylinositol-4,5-bisphosphate phosphodiesterase activity. It correlates well with the observation that neither alpha 1-adrenergic nor muscarinic receptors have been found in fast-twitch rabbit skeletal muscle. On basis of the respective enzyme activities estimations on maximal phosphatidylinositol turnover were made and a possible involvement of this signal pathway in excitation-contraction coupling has been discussed. Furthermore, calculations show that during a single twitch D-myo-inositol 1,4,5-trisphosphate concentration does not reach more than 2 nM. However, during a 4-s tetanus D-myo-inositol 1,4,5-trisphosphate can accumulate to a level which could effect force generation [Thieleczek and Heilmeyer (1986) Biochem. Biophys. Res. Commun. 135, 662] and aldolase distribution (Thieleczek et al., unpublished results).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
179
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
473-9
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:2537212-Animals, pubmed-meshheading:2537212-Centrifugation, Density Gradient, pubmed-meshheading:2537212-Inositol 1,4,5-Trisphosphate, pubmed-meshheading:2537212-Inositol Phosphates, pubmed-meshheading:2537212-Microsomes, pubmed-meshheading:2537212-Muscle Contraction, pubmed-meshheading:2537212-Muscles, pubmed-meshheading:2537212-Phosphatidylinositols, pubmed-meshheading:2537212-Phosphoinositide Phospholipase C, pubmed-meshheading:2537212-Phosphoric Diester Hydrolases, pubmed-meshheading:2537212-Phosphotransferases, pubmed-meshheading:2537212-Phosphotransferases (Alcohol Group Acceptor), pubmed-meshheading:2537212-Rabbits, pubmed-meshheading:2537212-Rats, pubmed-meshheading:2537212-Sarcoplasmic Reticulum, pubmed-meshheading:2537212-Subcellular Fractions, pubmed-meshheading:2537212-Sugar Phosphates
pubmed:year
1989
pubmed:articleTitle
Intracellular localization of inositol-phospholipid-metabolizing enzymes in rabbit fast-twitch skeletal muscle. Can D-myo-inositol 1,4,5-trisphosphate play a role in excitation-contraction coupling?
pubmed:affiliation
Institut für Physiologische Chemie, Abteilung für Biochemie Supramolekularer Systeme, Ruhr-Universität Bochum, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't