Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
37
pubmed:dateCreated
2002-9-9
pubmed:abstractText
Glucokinase (GK) activity is essential for the physiological regulation of insulin secretion by glucose. Because the enzyme exerts nearly total control over glucose metabolism in the beta-cell, even small changes in GK activity exert effects on glucose-stimulated insulin secretion and, consequently, the blood glucose concentration. Using quantitative imaging of multicolor fluorescent proteins fused to GK, we found that the association of GK with insulin granules is regulated by glucose in the beta-cell. Glucose stimulation increased the rate of fluorescence recovery after photobleaching of GK to insulin granules, indicating that GK is released into the cytoplasm after glucose stimulation. Changes in fluorescence resonance energy transfer between two different fluorescent protein variants inserted on opposing ends of GK were observed after glucose stimulation and correlated with increased enzyme activity. Furthermore, glucose-stimulated changes in GK regulation were blocked by two inhibitors of insulin secretion. Insulin treatment restored GK regulation in inhibited cells and stimulated GK translocation and activation by itself. Together, these data support a model for post-translational regulation of GK whereby insulin regulates both the association of GK with secretory granules and the activity of the enzyme within the pancreatic beta-cell.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
277
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34168-75
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
A functional link between glucokinase binding to insulin granules and conformational alterations in response to glucose and insulin.
pubmed:affiliation
Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.