Linked Life Data

7649079

Source:http://linkedlifedata.com/resource/pubmed/id/7649079

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1995-9-22
pubmed:abstractText
Studies of the relationship between PTH structure and function in the activation of protein kinases have revealed that different regions within the biologically active PTH-(1-34) peptide are responsible for different functions. The first two N-terminal amino acids are required for plasma membrane adenylyl cyclase stimulation, and the C-terminal region 29-32 is necessary for the translocating activity of protein kinase C. In the present study, we explored the structure-function relationship of human (h) PTH in the regulation of the vitamin D receptor (VDR) in osteoblast-like cells (ROS 17/2.8). VDR-rich cytosol extract was prepared after the confluent cells were incubated with different hPTH fragments for 16 h. hPTH-(1-34) at concentrations of 10(-9)-10(-7) M caused a dose-dependent decrease in VDR content from a control level of 70.2 +/- 2.2 fmol/mg protein to 62.1 +/- 3.3 (-16%) at 10(-9) M, 52.3 +/- 5.3 (-25.5%; P < 0.02) at 10(-8) M, and 45.5 +/- 3.5 fmol/mg protein (-35.3%; P = 0.001) at 10(-7) M (n = 6). hPTH-(1-31) also decreased VDR content from 65.5 +/- 3.6 to 55.2 +/- 7.9 (-19.5%) at 10(-9) M, 44.3 +/- 5.8 (-32.4%; P < 0.05) at 10(-8) M, and 40.6 +/- 3.2 fmol/mg protein (-38.9%; P < 0.05) at 10(-7) M (n = 6). Incubation of ROS 17/2.8 cells with 0.5 nM 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] led to up-regulation of VDR content by 340-370% of the control value. hPTH-(1-34) decreased the VDR up-regulatory effect of 1,25-(OH)2D3 from 340% to 230% of the control value at 10(-8) M (P < 0.0001) and 170% of the control value (P < 0.0001) at 10(-7) M, respectively (n = 6). hPTH-(1-31) also decreased the receptor up-regulatory effect of 1,25-(OH)2D3 from 370% to 286% (P < 0.02) at 10(-8) M and 220% (P < 0.002) at 10(-7) M, respectively (n = 6). hPTH-(3-34) and -(13-34) at concentrations of 10(-9)-10(-7) M did not decrease VDR content in either the absence or presence of 1,25-(OH)2D3. Quantitation of VDR messenger RNA by reverse transcription-polymerase chain reaction showed that PTH-(1-34) and -(1-31) at 10(-7) M, but not PTH-(3-34) and -(13-34), inhibited ROS 17/2.8 cell VDR gene expression in both the absence and presence of 1,25-(OH)2D3.(ABSTRACT TRUNCATED AT 400 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
136
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3735-42
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Structure-function relationship of human parathyroid hormone in the regulation of vitamin D receptor expression in osteoblast-like cells (ROS 17/2.8).
pubmed:affiliation
Department of Medicine, University of Chicago Pritzker School of Medicine, Illinois 60637, USA.
pubmed:publicationType
Journal Article