Cloning and expression of a unique short form of the porcine prolactin receptor

Abstract

Prolactin (PRL) is required not only for maintenance of gestation in pigs but also for mammary gland development and subsequent lactogenesis. The actions of PRL are modulated by both long and short isoforms of the PRL receptor (PRLR), where short isoforms can interfere with the essential signaling function of the long isoform. Using 3 0 RACE we have isolated a unique splice variant of the porcine PRLR (pPRLR) that contains a short intracellular domain of 38 aa that is encoded by splicing from exon 9 to a novel exon 11 located 17 . 5 kb downstream of exon 10 on chromosome 16. The short pPRLR was detected as a 42 kDa protein in membranes from porcine mammary glands. Functional analyses indicated that the short pPRLR functions as a dominant negative against the differentiative function of the long pPRLR and does not transduce a signal to the rat b-casein promoter. Differential abundance of long pPRLR and short pPRLR mRNA was established in a range of porcine tissues. The binding affinity of the short pPRLR for pPRL was lower (K d Z3 . 7 nM) than the affinity of the long pPRLR (K d Z1 . 6 nM) despite a fourfold higher level of binding sites for the short pPRLR. Our data raise the possibility that the short pPRLR in pigs may function independently from the long pPRLR, where the splicing strategy used to generate the short pPRLR likely evolved under different selection pressures to those acting on the long pPRLR.

Comparative genomics reveals tissue-specific regulation of prolactin receptor gene expression

“…1). The orientation and locations of exons 3 through 11 on the reverse strand of chromosome 16 were as described previously (Trott et al 2011), which are in accordance with the hPRLR gene that is located on the reverse strand of H. sapiens chromosome 5. From our annotation ( Fig.…”

“…Nulliparous Hampshire!Yorkshire female pigs (nZ11) were housed, killed and tissues sampled as described previously (Trott et al 2011). The pregnant pigs were unilaterally hysterectomised-ovariectomised and then killed at different stages of gestation, as described previously (Freking et al 2007, Trott et al 2009).…”

“…The expression levels of each transcript were calculated using an absolute quantification standard curve of cycles to threshold vs plasmid copy number (log 10 transformed). A relative standard curve for 18S rRNA was also prepared using fivefold serial dilutions of pooled cDNA that were amplified in duplicate using previously published primers (Trott et al 2011). All standard curves had a linear regression coefficient of determination of at least 99.1%.…”

“…All standard curves had a linear regression coefficient of determination of at least 99.1%. The average transcript copy number, determined from duplicates, was divided by the corresponding relative amount of 18S rRNA (Trott et al 2011).…”

Prolactin potentiates the activity of acid-sensing ion channels in female rat primary sensory neurons

“…In peripheral sensory neurons, ASICs are detected in axons, axon terminals and cell bodies, where their activation contributes to pain signaling (Price et al, 2001). It has been shown that ASICs play an important role in various pain conditions such as inflammatory pain, postoperative pain and migraine (Deval et al, 2011;Kellenberger and Schild, 2015;Trott et al, 2011).…”