Phosphorylation of Pit-1 by Cyclin-dependent Kinase 5 at Serine 126 is Associated With Cell Proliferation and Poor Prognosis in Prolactinomas
Background:
Pit-1 is a POU-homeodomain transcription factor, Cyclin-dependent kinase(CDK5)is a protein kinase that can phosphorylate many key transcription factors, but the mechanism of CDK5 phosphorylates Pit-1 is unclear.
Methods:
We generated an antibody that specifically recognizes phosphorylated serine at position 126 of Pit-1 (Ser126-Pit-1); we used western blotting to detect the level of Pit-1 phosphorylation and observed the proliferation and apoptosis of GH3 cells with different levels of Pit-1 phosphorylation by clone formation experiments, cell viability assays, and flow cytometry. ELISA was used to measure the level of PRL in the supernatant of GH3 cells. Tissue microarrays and immunohistochemistry were used to evaluate the expression of phosphorylation level of Ser126-Pit-1 (pSer126-Pit-1) in prolactinomas.
Results
Our data indicated that Ser126-Pit-1 is specifically phosphorylated by CDK5. pSer-126-Pit-1 can promote cell proliferation and PRL secretion. In addition, a higher level of pSer-126-Pit-1 correlates with a worse prognosis in patients with prolactinoma.
Conclusions
CDK5-mediated Ser126-Pit-1 phosphorylation regulates prolactinoma progression and PRL secretion.
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Posted 11 Aug, 2020
Phosphorylation of Pit-1 by Cyclin-dependent Kinase 5 at Serine 126 is Associated With Cell Proliferation and Poor Prognosis in Prolactinomas
Posted 11 Aug, 2020
Background:
Pit-1 is a POU-homeodomain transcription factor, Cyclin-dependent kinase(CDK5)is a protein kinase that can phosphorylate many key transcription factors, but the mechanism of CDK5 phosphorylates Pit-1 is unclear.
Methods:
We generated an antibody that specifically recognizes phosphorylated serine at position 126 of Pit-1 (Ser126-Pit-1); we used western blotting to detect the level of Pit-1 phosphorylation and observed the proliferation and apoptosis of GH3 cells with different levels of Pit-1 phosphorylation by clone formation experiments, cell viability assays, and flow cytometry. ELISA was used to measure the level of PRL in the supernatant of GH3 cells. Tissue microarrays and immunohistochemistry were used to evaluate the expression of phosphorylation level of Ser126-Pit-1 (pSer126-Pit-1) in prolactinomas.
Results
Our data indicated that Ser126-Pit-1 is specifically phosphorylated by CDK5. pSer-126-Pit-1 can promote cell proliferation and PRL secretion. In addition, a higher level of pSer-126-Pit-1 correlates with a worse prognosis in patients with prolactinoma.
Conclusions
CDK5-mediated Ser126-Pit-1 phosphorylation regulates prolactinoma progression and PRL secretion.
Figure 1
Figure 2
Figure 3
Figure 4