Identification of a cDNA Encoding a Long Form of Prolactin Receptor in Human Hepatoma and Breast Cancer Cells

Abstract

Human PRL receptor cDNA clones from hepatoma (Hep G2) and breast cancer (T-47D) libraries were isolated by using a rat PRL receptor cDNA probe. The nucleotide sequence predicts a mature protein of 598 amino acids with a much longer cytoplasmic domain than the rat liver PRL receptor. Although this extended region has additional segments of localized sequence identity with the human GH receptor, there is no identity with any consensus sequences known to be involved in hormonal signal transduction. This cDNA will be a valuable tool to better understand the role of PRL in the development and growth of human breast cancer.

Alternative splicing to exon 11 of human prolactin receptor gene results in multiple isoforms including a secreted prolactin-binding protein

“…The size of mRNA transcripts for hPRLR-SF1a, hPRLR-SF1b and hPRLR-LF concurred with the predicted sizes of 2, 1·9 and 3·5 kb respectively. Two PRLR mRNA transcripts of approximately 9 and 3·5 kb were detected in T47D cells, similar to previous results using Northern analysis of hPRLR-LF expression (Boutin et al 1989). Western analysis of FLAGtagged protein products indicated that SF1a-FLAG, SF1b-FLAG and LF-FLAG encoded translation products of approximately 57, 38 and 93 kDa respectively (Fig.…”

“…The PRLR is composed of an extracellular ligand-binding domain, a transmembrane region and an intracellular domain (Kelly et al 1989). The gene contains ten exons including five alternative exon 1 sequences, where only exons 3 through 10 are coding exons (Hu et al 1999(Hu et al , 2002.…”

“…Different isoforms (long form (LF), intermediate form (IF) and short form (SF) of the PRLR have been named for the length of their intracellular domain generated by alternative splicing of the PRLR gene (Ormandy et al 1998, Hu et al 1999. Functional clones have been characterized for the human (h)PRLR-LF (exons 1 to 10; Boutin et al 1989) and IF (same as hPRLR-LF but lacks part of exon 10; Kline et al 1999). The most extensively characterized isoform is the hPRLR-LF that transduces both mitogenic and differentiative signals (Lesueur et al 1991, O'Neal & Yu Lee 1994, Jabbour et al 1998, Llovera et al 2000.…”

Prolactin receptor signal transduction in cells of the immune system

“…2): the 'short' (PRLr-S, approximately 291 amino acids, approximately 45 kDa), 'long' (PRLr-L, approximately 592-598 amino acids, 80-85 kDa), and intermediate (PRLr-I, a deletion mutant missing amino acids 323-520 of the PRLr-L isoform, found in the PRL-dependent rat T-cell lymphoma line Nb2; 393 amino acids, approximately 65 kDa) (Boutin et al 1988, Ali et al 1991. In humans, two PRLr isoforms have been identified: the long (Boutin et al 1989) and a novel intermediate isoform, recently identified in our laboratory (Clevenger et al 1995a). All PRLr isoforms are homologous in their extracellular and transmembrane domain; alternative mRNA splicing accounts for the differing sizes of the cytoplasmic domain, with the exception of the Nb2 mutant form, which is believed to result from a mutation in the exon encoding for rat PRLr intracellular domain (Ali et al 1991).…”

Retinoic acid modulates prolactin receptor expression and prolactin-induced STAT-5 activation in breast cancer cells in vitro

“…PCRs were performed in a volume of 25 µl. The primers used were: 5′-TGC ACC ACC AAC TGC TTA GCA-3′ and 5′-GAA GTC AGA GGA GAC CAC CTG-3′ for glyceraldehyde phosphate dehydrogenase (GAPDH), yielding a 405-bp fragment spanning positions 513-918 of human cDNA (Tso et al, 1985), and 5′-ACT TAC ATA GTT CAG CCA GAC C-3′ and 5′-TGA ATG AAG GTC GCT GGA CTC C-3′ for PRL-R, yielding a 310-bp fragment spanning positions 363-673 of human cDNA and recognizing the extracellular form of PRL-R (Boutin et al, 1989). Thirty cycles were performed in a thermocycler.…”