Cloning of a novel rat placental prolactin-like protein C-related cDNA.
Prolactin-like protein C (PLP-C) is a major rat placental protein which is expressed during the second half of pregnancy and belongs to the growth hormone-prolactin family. Here we report on the isolation of overlapping rat placental cDNAs which specify a transcript of 915 base pairs and predict a 205-amino acid translated product. The full-length cDNA shares 93% homology with the nucleotide sequence reported for PLP-C, and the putative protein, which we designate PCRP (prolactin-like protein C-related protein), exhibits 88% homology with the PLP-C precursor protein. PCRP lacks the signal sequence and the first 2 N-terminal cysteine residues present in PLP-C. Northern blot analysis indicated the basal zone-specific expression of PCRP mRNA, with no detectable expression in decidua and labyrinth. Southern blot analysis of rat genomic DNA using PCRP cDNA as a probe demonstrated multiple hybridization bands, suggestive of a family of genes encoding prolactin-like proteins. Western immunoblot analysis of basal zone culture media using a PCRP antipeptide antiserum revealed at least 5 immunoreactive proteins. The existence of a PLP-C family of proteins in rat placenta after midpregnancy suggests their functional significance in the maintenance of pregnancy and fetal development.
Conliffe
P R
PR
Department of Pharmacology, University of Florida, Gainesville 32610, USA.
Simmen
R C
RC
Buhi
W C
WC
Shiverick
K T
KT
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics*; D005260:Female; D008969:Molecular Sequence Data; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics*; D051381:Rats; D016415:Sequence Alignment
D018076:DNA, Complementary; D011257:Pregnancy Proteins; C502145:Prl8a3 protein, rat