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Disease
Symptom
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Enzyme
Compound
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Target Concepts:
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Query: UNIPROT:P01189 (
beta-endorphin
)
21,003
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Steroid hormone biosynthesis in the adrenal cortex is controlled by the peptide hormone
adrenocorticotropin
(ACTH), which acts to increase intracellular cAMP, resulting in the activation of cAMP-dependent protein kinase (PKA) and subsequent increase in steroidogenic gene transcription. We have identified three proteins interacting with the human CYP17 cAMP responsive sequence (CRS): steroidogenic factor 1 (SF-1),
p54nrb
, and polypyrimidine tract-binding protein-associated splicing factor (PSF). Nuclear extracts isolated from cAMP stimulated of H295R cells showed cAMP-inducible binding to the human CYP17 (hCYP17) CRS. This cAMP-inducible binding was dependent on a dual-specificity phosphatase (DSP). DSP activity was subsequently shown to be is essential for conveying ACTH/cAMP-stimulated transcription of several steroidogenic genes in the human adrenal cortex. We report here that the transactivation potential of SF-1 is also dependent on phosphatase activity; suggesting that SF-1 is dephosphorylated in response to ACTH/cAMP stimulation. Finally, we demonstrate a role for mitogen-activated protein kinase phosphatase 1 (MKP-1), a nuclear DSP, in conveying SF-1-dependent transcription of an hCYP17 promoter-reporter construct in the H295R human adrenocortical cell line. We conclude that a DSP, possibly MKP-1, is essential for enhancing hCYP17 transcription in the adrenal cortex by desphosphorylating of SF-1, thereby increasing the binding affinity of SF-1,
p54nrb
, and PSF for the hCYP17 promoter.
...
PMID:Transcriptional complexes at the CYP17 CRS. 1253 Jun 62
Glucocorticoid production in the adrenal cortex is activated in response to an increase in cyclic AMP (cAMP) signaling. The nuclear protein
p54(nrb)
/
NONO
belongs to the Drosophila behavior/human splicing (DBHS) family and has been implicated in several nuclear processes, including transcription, splicing, and RNA export. We previously identified
p54(nrb)
/
NONO
as a component of a protein complex that regulates the transcription of CYP17A1, a gene required for glucocorticoid production. Based on the multiple mechanisms by which
p54(nrb)
/
NONO
has been shown to control gene expression and the ability of the protein to be recruited to the CYP17A1 promoter, we sought to further define the molecular mechanism by which
p54(nrb)
/
NONO
confers optimal cortisol production. We show here that silencing
p54(nrb)
/
NONO
expression in H295R human adrenocortical cells decreases the ability of the cells to increase intracellular cAMP production and subsequent cortisol biosynthesis in response to
adrenocorticotropin
hormone (ACTH) stimulation. Interestingly, the expression of multiple phosphodiesterase (PDE) isoforms, including PDE2A, PDE3A, PDE3B, PDE4A, PDE4D, and PDE11A, was induced in
p54(nrb)
/
NONO
knockdown cells. Investigation of the mechanism by which silencing of
p54(nrb)
/
NONO
led to increased expression of select PDE isoforms revealed that
p54(nrb)
/
NONO
regulates the splicing of a subset of PDE isoforms. Importantly, we also identify a role for
p54(nrb)
/
NONO
in regulating the stability of PDE transcripts by facilitating the interaction between the exoribonuclease XRN2 and select PDE transcripts. In summary, we report that
p54(nrb)
/
NONO
modulates cAMP-dependent signaling, and ultimately cAMP-stimulated glucocorticoid biosynthesis by regulating the splicing and degradation of PDE transcripts.
...
PMID:p54nrb/NONO regulates cyclic AMP-dependent glucocorticoid production by modulating phosphodiesterase mRNA splicing and degradation. 2560 30