Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1983-7-8
pubmed:abstractText
For a variety of ligand states, adenylate cyclase activity in the presence of Mn2+ was greater than with Mg2+. Trypsin treatment of intact hepatocytes, under conditions which destroy cell surface glucagon receptors, led to a first order loss of glucagon-stimulated adenylate cyclase activity in isolated membranes assayed in the presence of Mn2+ whether or not GTP (100 microM) was present in the assays. Arrhenius plots of basal activity exhibited a break at around 22 degrees C, those with NaF were linear and those with glucagon +/- GTP (100 microM) were biphasic with a break at around 28 degrees C. It is suggested that Mn2+ perturbs the coupling interaction between the glucagon receptor and catalytic unit of adenylate cyclase at the level of the guanine nucleotide regulatory protein. This appears to take the form of Mn2+ preventing GTP from initiating glucagon's activation of adenylate cyclase through a collision coupling mechanism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
155
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
311-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Mechanism of glucagon activation of adenylate cyclase in the presence of Mn2+.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't