Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-7-1
pubmed:abstractText
Ca2+ and other divalent cations modulate parathyroid hormone secretion by interacting with cell-surface Ca2+-sensing receptors (CaRs). We assessed the ability of these receptors to couple to Ca2+ mobilization, inositol phosphate (InsP) accumulation, and cyclic AMP production in different expression systems. In Xenopus laevis oocytes injected with bovine parathyroid CaR cRNA, the addition of extracellular cations to 1.5 mM Ca2+, 5.5 mM Mg2+, or 10 microM Gd3+ significantly increased 45Ca efflux (p < 0.01). InsP accumulation also increased dramatically when adding these cations to human embryonic kidney (HEK) 293 cells stably transfected with wild-type bovine parathyroid CaR cDNA. Raising the extracellular [Ca2+] ([Ca2+]o) from 0.1 to > 1.4 mM in oocytes and to > 1.0 mM in HEK 293 cells stimulated significant increments in 45Ca efflux and InsP accumulation, respectively (p < 0.05). In contrast, Ca2+ and Mg2+ increased InsPs to a lesser extent in COS 7 cells transiently transfected with CaR cDNA. In HEK 293 cells stably expressing CaR cDNA, there were significant reductions in cAMP content when adding high Ca2+, Mg2+, Gd3+, or the CaR modulator NPS R-467. Three region-specific anti-CaR peptide antisera immunoblotted bands of approximately 140 and 155 kDa in membranes from CaR-transfected HEK 293 cells and bovine parathyroid tissue. Immunocytochemistry demonstrated strong cell-surface staining in CaR-transfected HEK 293 cells and parathyroid tissue, which was absent when antisera were preabsorbed with CaR peptides. These results indicate that the activation of the recombinant CaR by extracellular Ca2+ can couple negatively to adenylate cyclase but positively to phospholipase C (PLC), the latter at physiological [Ca2+]o.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0884-0431
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
570-80
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:9556057-Amino Acid Sequence, pubmed-meshheading:9556057-Aniline Compounds, pubmed-meshheading:9556057-Animals, pubmed-meshheading:9556057-COS Cells, pubmed-meshheading:9556057-Calcium, pubmed-meshheading:9556057-Calcium-Binding Proteins, pubmed-meshheading:9556057-Cattle, pubmed-meshheading:9556057-Cell Line, pubmed-meshheading:9556057-Cyclic AMP, pubmed-meshheading:9556057-Female, pubmed-meshheading:9556057-Humans, pubmed-meshheading:9556057-Immune Sera, pubmed-meshheading:9556057-Immunoblotting, pubmed-meshheading:9556057-Immunohistochemistry, pubmed-meshheading:9556057-Inositol Phosphates, pubmed-meshheading:9556057-Kidney, pubmed-meshheading:9556057-Magnesium, pubmed-meshheading:9556057-Molecular Sequence Data, pubmed-meshheading:9556057-Oocytes, pubmed-meshheading:9556057-Peptide Biosynthesis, pubmed-meshheading:9556057-Transfection, pubmed-meshheading:9556057-Xenopus laevis
pubmed:year
1998
pubmed:articleTitle
Coupling of calcium receptors to inositol phosphate and cyclic AMP generation in mammalian cells and Xenopus laevis oocytes and immunodetection of receptor protein by region-specific antipeptide antisera.
pubmed:affiliation
Department of Veterans Affairs Medical Center, Department of Medicine, University of California, San Francisco 94121, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't