{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T21:56:53Z","timestamp":1791237413069,"version":"4.1.0"},"reference-count":0,"publisher":"American Diabetes Association","issue":"12","content-domain":{"domain":["diabetesjournals.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1998,12,1]]},"abstract":"<jats:p>Glutamine:fructose-6-phosphate amidotransferase (GFA) is the rate-limiting enzyme in hexosamine biosynthesis, an important pathway for cellular glucose sensing. Human GFA has two potential sites for phosphorylation by cAMP-dependent protein kinase A (PKA). To test whether GFA activity is regulated by cAMP-dependent phosphorylation, rat aortic smooth muscle cells were treated in vivo with cAMP-elevating agents, 10 micromol\/l forskolin, 1 mmol\/l 8-Br-cAMP, or 3-isobutyl-1-methylxanthine. All treatments resulted in rapid and significant increases (2- to 2.4-fold) in GFA activity assayed in cytosolic extracts. Maximal effects of forskolin were observed at 10 micromol\/l and 60 min. Preincubation of cells with cycloheximide did not abolish the effect of forskolin. Incubation of cytosolic extracts at 37 degrees C for 10 min in a buffer without phosphatase inhibitors led to a 79% decrease of GFA activity. This loss of activity was inhibited by the addition of phosphatase inhibitors (5 mmol\/l sodium orthovanadate, 50 mmol\/l sodium fluoride, or 5 mmol\/l EDTA, but not 100 nmol\/l okadaic acid), suggesting that GFA undergoes rapid dephosphorylation by endogenous phosphatases. Purified GFA is phosphorylated in vitro by purified PKA, resulting in a 1.7-fold increase in GFA activity. Treatment of GFA with purified protein kinase C had no effect. We conclude that GFA activity may be modulated by cAMP-dependent phosphorylation.<\/jats:p>","DOI":"10.2337\/diabetes.47.12.1836","type":"journal-article","created":{"date-parts":[[2007,3,6]],"date-time":"2007-03-06T19:04:22Z","timestamp":1173207862000},"page":"1836-1840","update-policy":"https:\/\/doi.org\/10.2337\/ada-journal-policies","source":"Crossref","is-referenced-by-count":52,"title":["Regulation of glutamine:fructose-6-phosphate amidotransferase by cAMP-dependent protein kinase."],"prefix":"10.2337","volume":"47","author":[{"given":"J","family":"Zhou","sequence":"first","affiliation":[{"name":"Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Q K","family":"Huynh","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R T","family":"Hoffman","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E D","family":"Crook","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M C","family":"Daniels","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"E A","family":"Gulve","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D A","family":"McClain","sequence":"additional","affiliation":[{"name":"Department of Medicine, University of Mississippi Medical Center, Jackson 39216, USA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1167","container-title":["Diabetes"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.org\/diabetes\/diabetes\/article-pdf\/47\/12\/1836\/552289\/9836513.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/diabetesjournals.org\/diabetes\/article-pdf\/47\/12\/1836\/552289\/9836513.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,11,2]],"date-time":"2022-11-02T16:44:05Z","timestamp":1667407445000},"score":1,"resource":{"primary":{"URL":"https:\/\/diabetesjournals.org\/diabetes\/article\/47\/12\/1836\/9689\/Regulation-of-glutamine-fructose-6-phosphate"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1998,12,1]]},"references-count":0,"journal-issue":{"issue":"12","published-print":{"date-parts":[[1998,12,1]]}},"URL":"https:\/\/doi.org\/10.2337\/diabetes.47.12.1836","relation":{},"ISSN":["0012-1797","1939-327X"],"issn-type":[{"value":"0012-1797","type":"print"},{"value":"1939-327X","type":"electronic"}],"subject":[],"published":{"date-parts":[[1998,12,1]]}}}