Τομέας Φυσιολογίας Ζώων και Ανθρώπου
Library of the School of Science

2015-08-31

2015

Βαβουράκη Νικολέτα

Σπυρίδων Ευθυμιόπουλος Αναπλ. Καθηγητής (επιβλέπων)

Η ενεργοποίηση του μεταγραφικού παράγοντα STAT5A από το μ οπιοειδή και το ντοπαμινεργικό υποδοχέα D4.2

Greek

The m opioid and D4.2 dopaminergic receptor mediated activation of the transcriptional factor STAT5A

The opioid and dopaminergic receptors inhere within the superfamily of the
seven-transmembrane receptors (7TMRs), which are implicated in cellular
mechanisms of paramount importance regarding the proper functioning of the
body. Previous studies of the Cellular Signalling and Molecular Pharmacology
Laboratory have demonstrated that the mu opioid receptor (μOR) apart from its
ability to activate Gi/o proteins, it may lead to the phosphorylation of the
transcriptional factor STAT5A. Based on the later and taking also into account
that the opioid receptors when activated can lead to a perceptible release of
dopamine, we wanted to investigate whether the signalling of the dopaminergic
receptor D4.2 (D4.2R) alters the μOR mediated activation of STAT5A. Our results
unveil that when co-activating the two receptors, the levels of phosphorylated
STAT5A exceed those observed in both single activations of μOR with morphine
and of D4.2R with PD168077, respectively. The aforementioned remark implies
that the co-activation enhances the signalling of the receptors, perhaps due to
some kind of synergistic effect. On the other hand, when another ligand of μOR
was used -the synthetic peptide DAMGO-, such augmentation in the levels of
phospholylated STAT5A in the co activating state, compared with the single
activation state, was absent. This variance on the signalling response can be
explained based on the ligand dependent signalling model, which claims that a
single receptor can activate distinct signalling pathways when bound with
different ligands. The above results underline the complexity of the signalling
properties of the opioid receptors. Further studies on opioid receptors should
be conducted in order to elucidate their multiple functions

Opioid receptors , Dopaminergic receptors , STAT5A, Phosphorylation

No

0

Yes

199

viii, 76, XII

File access is restricted.

https://pergamos.lib.uoa.gr/uoa/dl/object/1324250