Testosterone inhibits cAMP-induced de Novo synthesis of Leydig cell cytochrome P-450(17 alpha) by an androgen receptor-mediated mechanism.

D B Hales; L L Sha; A H Payne

doi:10.1016/s0021-9258(18)60944-5

Stimulation of de novo synthesis of cytochrome P-450 by phenobarbital in primary nonproliferating cultures of adult rat hepatocytes.

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.79.9.2922 ◽

1982 ◽

Vol 79 (9) ◽

pp. 2922-2926 ◽

Cited By ~ 30

Author(s):

S. Newman ◽

P. S. Guzelian

Keyword(s):

De Novo ◽

Rat Hepatocytes ◽

De Novo Synthesis ◽

Adult Rat ◽

Adult Rat Hepatocytes ◽

Cytochrome P 450 ◽

Stimulation Of

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Induction of cytochrome P-450 by glucocorticoids in rat liver. I. Evidence that glucocorticoids and pregnenolone 16 alpha-carbonitrile regulate de novo synthesis of a common form of cytochrome P-450 in cultures of adult rat hepatocytes and in the liver in vivo.

Journal of Biological Chemistry ◽

10.1016/s0021-9258(17)43507-1 ◽

1984 ◽

Vol 259 (3) ◽

pp. 1999-2006 ◽

Cited By ~ 6

Author(s):

E G Schuetz ◽

S A Wrighton ◽

J L Barwick ◽

P S Guzelian

Keyword(s):

Rat Liver ◽

De Novo ◽

Rat Hepatocytes ◽

De Novo Synthesis ◽

Adult Rat ◽

Adult Rat Hepatocytes ◽

Cytochrome P 450

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Phosphorylation of androgen receptor isoforms

Biochemical Journal ◽

10.1042/bj20040683 ◽

2004 ◽

Vol 383 (2) ◽

pp. 267-276 ◽

Cited By ~ 36

Author(s):

Hao Yun WONG ◽

Jan A. BURGHOORN ◽

Marije van LEEUWEN ◽

Petra E. de RUITER ◽

Esther SCHIPPERS ◽

...

Keyword(s):

Androgen Receptor ◽

De Novo ◽

Major Change ◽

Reversed Phase ◽

Mitogen Activated Protein Kinase ◽

Reversed Phase Hplc ◽

De Novo Synthesis ◽

Elution Pattern ◽

Receptor Isoforms ◽

Mitogen Activated Protein

Phosphorylation of the human AR (androgen receptor) is directly correlated with the appearance of at least three AR isoforms on an SDS/polyacrylamide gel. However, it is still not clear to what extent phosphorylation is involved in the occurrence of isoforms, which sites are phosphorylated and what are the functions of these phosphosites. The human AR was expressed in COS-1 cells and AR phosphorylation was studied further by mutational analyses and by using reversed-phase HPLC and MS. The reversed-phase HPLC elution pattern of the three isoforms revealed that Ser-650 was phosphorylated constitutively. After de novo synthesis, only Ser-650 was phosphorylated in the smallest isoform of 110 kDa and both Ser-650 and Ser-94 were phosphorylated in the second isoform of 112 kDa. The hormone-induced 114 kDa isoform shows an overall increase in phosphorylation of all the isolated peptides. The activities of the Ser–Ala substitution mutant S650A (Ser-650→Ala) was found to be identical with wild-type AR activation in four different cell lines and three different functional analyses, e.g. transactivation, N- and C-terminal-domain interaction and co-activation by transcriptional intermediary factor 2. This was also found for mutants S94A and S515A with respect to transactivation. However, the S515A mutation, which should eliminate phosphorylation of the potential mitogen-activated protein kinase site, Ser-515, resulted in an unphosphorylated form of the peptide containing Ser-650. This suggests that Ser-515 can modulate phosphorylation at another site. The present study shows that the AR isoform pattern from AR de novo synthesis is directly linked to differential phosphorylation of a distinct set of sites. After mutagenesis of these sites, no major change in functional activity of the AR was observed.

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Characterization of Monocyte-Associated Factor V

Thrombosis and Haemostasis ◽

10.1055/s-0038-1649565 ◽

1993 ◽

Vol 70 (02) ◽

pp. 273-280 ◽

Cited By ~ 5

Author(s):

Janos Kappelmayer ◽

Satya P Kunapuli ◽

Edward G Wyshock ◽

Robert W Colman

Keyword(s):

Monoclonal Antibody ◽

Light Chain ◽

Peripheral Blood ◽

De Novo ◽

Factor V ◽

Blood Monocytes ◽

De Novo Synthesis ◽

Hep G2 ◽

Hep G2 Cells ◽

Peripheral Blood Monocytes

SummaryWe demonstrate that in addition to possessing binding sites for intact factor V (FV), unstimulated peripheral blood monocytes also express activated factor V (FVa) on their surfaces. FVa was identified on the monocyte surface by monoclonal antibody B38 recognizing FVa light chain and by human oligoclonal antibodies H1 (to FVa light chain) and H2 (to FVa heavy chain) using immunofluorescence microscopy and flow cytometry. On Western blots, partially cleaved FV could be identified as a 220 kDa band in lysates of monocytes. In addition to surface expression of FVa, monocytes also contain intracellular FV as detected only after permeabilization by Triton X-100 by monoclonal antibody B10 directed specifically to the Cl domain not present in FVa. We sought to determine whether the presence of FV in peripheral blood monocytes is a result of de novo synthesis.Using in situ hybridization, no FV mRNA could be detected in monocytes, while in parallel control studies, factor V mRNA was detectable in Hep G2 cells and CD18 mRNA in monocytes. In addition, using reverse transcriptase and the polymerase chain reaction, no FV mRNA was detected in mononuclear cells or in U937 cells, but mRNA for factor V was present in Hep G2 cells using the same techniques. These data suggest that FV is present in human monocytes, presumably acquired by binding of plasma FV, and that the presence of this critical coagulation factor is not due to de novo synthesis.

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Platelets Stimulate Thromboplastin Synthesis in Human Endothelial Cells

Thrombosis and Haemostasis ◽

10.1055/s-0038-1657323 ◽

1983 ◽

Vol 49 (02) ◽

pp. 069-072 ◽

Cited By ~ 20

Author(s):

U L H Johnsen ◽

T Lyberg ◽

K S Galdal ◽

H Prydz

Keyword(s):

Endothelial Cells ◽

De Novo ◽

Umbilical Vein ◽

Time Dependent ◽

De Novo Synthesis ◽

Human Endothelial Cells ◽

Tumor Promotor ◽

Coagulation Assay ◽

Platelet Aggregates ◽

Umbilical Vein Endothelial Cells

SummaryHuman umbilical vein endothelial cells in culture synthesize thromboplastin upon stimulation with phytohaemagglutinin (PHA) or the tumor promotor 12-O-tetradecanoyl-phorbol-13-acetate (TPA). The thromboplastin activity is further strongly enhanced in a time dependent reaction by the presence of gel-filtered platelets or platelet aggregates. This effect was demonstrable at platelet concentrations lower than those normally found in plasma, it may thus be of pathophysiological relevance. The thromboplastin activity increased with increasing number of platelets added. Cycloheximide inhibited the increase, suggesting that de novo synthesis of the protein component of thromboplastin, apoprotein III, is necessary.When care was taken to remove monocytes no thromboplastin activity and no apoprotein HI antigen could be demonstrated in suspensions of gel-filtered platelets, platelets aggregated with thrombin or homogenized platelets when studied with a coagulation assay and an antibody neutralization technique.

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