Disease relevance of PRLR

• The cDNA of the extracellular domain of bovine prolactin receptor (bPRLR-ECD) was cloned and expressed at high yield as an insoluble protein in Escherichia coli [1].

High impact information on PRLR

• A 7-fold increase in a prolactin receptor occurred as a function of cell cycle progression; accumulation of a 1.6-kilobase prolactin receptor mRNA increased approximately 2-fold [2].
• These studies define the basis of cellular trafficking of PRLR isoforms and increase our understanding of control of target cell responsiveness by PRL [3].
• We have analyzed the ability of each form of rat PRLR to transduce lactogenic signals in a bovine mammary gland epithelial cell line [4].
• When the biological activity of each form of PRLR was assessed by transient transfection, we found that the long form was able to activate the beta-casein gene promoter and that the short form was inactive [4].
• Similarly, the short form of the PRLR was not detected in nuclei of transfected COS cells upon PRL treatment [5].

Biological context of PRLR

• Furthermore, the data derived from coexpression of LPRLR and PRLR mutants confirm a crucial role of the C-terminal tyrosine residue in lactogenic signaling and the dimerization of PRLRs [4].
• PRL receptor (PRLR) signal transduction supports PRL-induced growth/differentiation processes [6].
• We herein report new evidence that the QTL effect on chromosome 20 in Finnish Ayrshire can be explained by variation in two distinct genes, growth hormone receptor (GHR) and prolactin receptor (PRLR) [7].
• The present study demonstrates for the first time the expressions of PRL and PRLR mRNA in bovine CL throughout the luteal phase [8].
• The objective of this study was to determine the effects of exposure to different lengths of daylight during the dry period on circulating PRL and PRL receptor (PRL-R) mRNA expression in lymphocytes and mammary tissue during the transition to lactation [9].

Anatomical context of PRLR

• Clearly, our results provide evidence that internalization of the plasma membrane PRLR does not lead to nuclear translocation of the receptor, or part of it, in most fibroblasts and epithelial cells at physiological concentrations of PRL [5].
• During the dry period, PRL and PRL-R mRNA were analyzed biweekly in plasma and lymphocytes, respectively [9].
• Both probes detected identical transcripts, suggesting that primarily the long form of PRL-R is expressed in the sheep pituitary gland [10].
• Partial purification and characterization of bovine mammary gland prolactin receptor [11].
• Affinity cross-linking of 125I-labelled human GH to mammary microsomes confirmed that the M(r) 36,000 protein was a bovine prolactin receptor [12].

Associations of PRLR with chemical compounds

• Using rhodamine-labeled PRL, we observed specific PRL uptake by these cells that suggested the presence of a PRL receptor [13].
• Daily injections of bGH or bLH, alone or in combination, or estrogens with PVP failed to restore PRL-R [14].
• Scatchard analysis demonstrated that the effect of N-ethylmaleimide resulted from loss of receptor-binding capacity without any substantial effect on the affinity of the prl receptor for hormone [15].
• T4 replacement reversed the effects of thyrocyte ablation on MUP mRNA in females and on Prl receptor mRNA in males.2+ Despite the many physiological changes induced by thyrocyte ablation, ablated mice have been maintained for up to 1 year without thyroid hormone supplementation [16].
• Neither insulin secretion nor the relative amount of PRL-R mRNA was affected by estradiol (100 ng/ml) [17].

Other interactions of PRLR

• The results provide strong evidence that the effect of PRLR S18N polymorphism is distinct from the GHR F279Y effect [7].
• Whether the effect of IFN-tau on PRL-R expression is mediated directly or influenced, at least in part, by progesterone remains to be elucidated [18].
• Using ribonuclease protection assay procedures, we compared endometrial PRL-R mRNA levels in ewes that were intrauterine injected with either 2 mg bovine serum albumin or 2 mg recombinant ovine IFN-tau on day 10 of the oestrous cycle (day 0 = day of oestrus) [18].

Analytical, diagnostic and therapeutic context of PRLR

• The rat PRLR forms were expressed and detected by RT-PCR, indirect immunofluorescence, and cell surface ligand binding [4].
• Mammary expression of suppressors of cytokine signaling (SOCS)-1, -2, and -3; the long form of PRL-receptor; and alpha-lactalbumin mRNA was measured by real-time reverse-transcription PCR [19].
• Translation of the PRL-R mRNA was confirmed by Western blot analysis [10].
• The identification of PRL-R in specific pituitary cell types was carried out by immunocytochemistry [10].
• At position 90 the bulk of the residue was the most important factor in modulating biological activity in either the rat Nb2 cell bioassay or PRL receptor binding [20].

References