The prolactin receptor from the brushtail possum (Trichosurus vulpecula): cDNA cloning, expression and functional analysis.
A full length, prolactin receptor cDNA clone has been isolated from the brushtail possum (Trichosurus vulpecula). This clone encodes a 625 amino acid protein which shares 60-70 and 54% sequence identity with prolactin receptor (long form) sequences from mammalian and avian species, respectively. Sequence similarity was highest in the extra-cellular, hormone-binding domain and in specific regions of the intracellular domain which regulates prolactin receptor signalling in cells. Prolactin receptor mRNA was detected in a wide range of possum tissues and in the mammary gland the PRL-R gene was differentially expressed during lactation with peak mRNA levels being detected during the first 6 days of lactation and after day 115 throughout late lactation. This pattern of PRL-R mRNA expression in the mammary gland is similar to that observed for circulating prolactin in the lactating possum. In CHO cells transiently transfected with the possum prolactin receptor, expression of a beta-lactoglobulin promoter/reporter gene construct was increased 3-fold by adding prolactin. The possum prolactin receptor is therefore capable of binding ovine prolactin and activating the Jak2/Stat5 signalling cascade. This provides evidence for the highly conserved nature of the prolactin signalling pathway in mammalian evolution.
Demmer
J
J
Dairy Science Group, AgResearch, Ruakura Research Centre, Hamilton, New Zealand. demmerj@agresearch.cri.nz
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002417:Cattle; D003001:Cloning, Molecular; D016384:Consensus Sequence; D006224:Cricetinae; D018076:DNA, Complementary; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007774:Lactation / Q000502:physiology*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008969:Molecular Sequence Data; D009893:Opossums; D011388:Prolactin / Q000097:blood; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D051381:Rats; D011981:Receptors, Prolactin / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic; D014162:Transfection
D018076:DNA, Complementary; D012333:RNA, Messenger; D011981:Receptors, Prolactin; D011993:Recombinant Fusion Proteins; D011388:Prolactin