+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

In vitro expression of long and short ovine prolactin receptors: activation of Jak2/STAT5 pathway is not sufficient to account for prolactin signal transduction to the ovine beta-lactoglobulin gene promoter

In vitro expression of long and short ovine prolactin receptors: activation of Jak2/STAT5 pathway is not sufficient to account for prolactin signal transduction to the ovine beta-lactoglobulin gene promoter

Journal of Molecular Endocrinology 23(2): 125-136

The recent finding that sheep had long (l-oPRLR) and short (s-oPRLR) prolactin receptors provided new tools to further explore prolactin signaling to target genes. Here we used CHO cells transfected with l-oPRLR or s-oPRLR cDNAs to compare the activation of known key steps of prolactin signaling by the two receptors. We found that prolactin stimulated l-oPRLR tyrosine phosphorylation, although it lacked the last tyrosine residue found in other long prolactin receptors. In addition, l-oPRLR and s-oPRLR both responded to prolactin stimulation by (1) Janus kinase 2 (Jak2) tyrosine phosphorylation, (2) DNA-binding activation of signal transducer and activator of transcription 5 (STAT5), (3) stimulation of transcription from a promoter made of six repeats of STAT5-responsive sequence. However, although it contains STAT5-binding consensus sequences, the ovine beta-lactoglobulin promoter (-4000 to +40) was transactivated by l-oPRLR, but not by s-oPRLR. Taken together, our results indicate that activation of Jak2/STAT5 pathway alone is not sufficient to account for prolactin-induced transcription of this milk protein gene, and that sequences of its promoter, other than STAT5-specific sequences, account for the opposite transcriptional activation capabilities of l-oPRLR and s-oPRLR.

Please choose payment method:

(PDF emailed within 0-6 h: $19.90)

Accession: 010813845

Download citation: RISBibTeXText

PMID: 10514551

DOI: 10.1677/jme.0.0230125

Related references

Prolactin signal transduction to milk protein genes: Carboxy-terminal part of the prolactin receptor and its tyrosine phosphorylation are not obligatory for JAK2 and STAT5 activation. Molecular & Cellular Endocrinology 127(2): 155-169, 1997

JAK2 and STAT5, but not JAK1 and STAT1, are required for prolactin-induced beta-lactoglobulin transcription. Molecular Endocrinology 11(8): 1180-1188, 1997

Differential signal transduction of the short, Nb2, and long prolactin receptors. Activation of interferon regulatory factor-1 and cell proliferation. Journal of Biological Chemistry 269(42): 26076-26082, 1994

Modulation of prolactin receptors in the rat hypothalamus in response to changes in serum concentration of endogenous prolactin or to ovine prolactin administration. Brain Research. 663(2): 244-250, 1994

Short-term regulation of prolactin receptors in the liver, mammary gland and kidney of pregnant and lactating rats infused with ovine prolactin or human growth hormone. Molecular and Cellular Endocrinology 46(3): 235-244, 1986

Proline-rich sequence-mediated Jak2 association to the prolactin receptor is required but not sufficient for signal transduction. Journal of Biological Chemistry 270(18): 10664-10670, 1995

Expression of functional prolactin receptors in nonpregnant human endometrium: janus kinase-2, signal transducer and activator of transcription-1 (STAT1), and STAT5 proteins are phosphorylated after stimulation with prolactin. Journal of Clinical Endocrinology and Metabolism 83(7): 2545-2553, 1998

Ovine placental lactogen-induced heterodimerization of ovine growth hormone and prolactin receptors in living cells is demonstrated by fluorescence resonance energy transfer microscopy and leads to prolonged phosphorylation of signal transducer and activator of transcription (STAT)1 and STAT3. Endocrinology 144(8): 3532-3540, 2003

An immunohistochemical approach to monitor the prolactin-induced activation of the JAK2/STAT5 pathway in pancreatic islets of Langerhans. Journal of Histochemistry and Cytochemistry 50(3): 365-383, 2002

Prolactin regulates ZNT2 expression through the JAK2/STAT5 signaling pathway in mammary cells. American Journal of Physiology. Cell Physiology 297(2): C369-C377, 2009

Characterization of a rat uterine cell line, U(III) cells: prolactin (PRL) expression and endogenous regulation of PRL-dependent genes; estrogen receptor beta, alpha(2)-macroglobulin, and decidual PRL involving the Jak2 and Stat5 pathway. Endocrinology 142(3): 1242-1250, 2001

Receptors for lactogenic hormones in the ovine corpus luteum. II: Specific inactivation of ovine prolactin. Journal of Endocrinology 113(3): 375-381, 1987

Increase in nuclear translocation of STAT5 and expression of FRAs in neuroendocrine dopaminergic neurons following ovine prolactin treatment. Society for Neuroscience Abstracts 25(1-2): 1186, 1999

Modulation of testicular receptors for LH, FSH and prolactin by the administration of ovine prolactin in mature rat. Endocrinologia Japonica 33(4): 469-477, 1986

Prolactin receptors in tilapia sarotherodon mossambicus tissues binding studies using iodine 125 labeled ovine prolactin. General & Comparative Endocrinology 56(1): 19-23, 1984