Characterization of a prolactin-inducible gene, clone 15, in T cells.

Abstract

To examine how PRL regulates lymphocyte proliferation, a number of PRL-activated genes were identified from a PRL-dependent rat T lymphoma cell line, Nb2. One of the downstream genes in the PRL signaling cascade was identified as clone 15 (c15). PRL stimulation of quiescent Nb2 T cells results in the expression of a 1.7-kilobase c15 mRNA, which reaches maximum levels between 8 and 10 h after stimulation. Corresponding [3H]thymidine incorporation experiments show that the maximum level of c15 mRNA expression correlates with the G1/S transition phase of the cell cycle. Sequencing of approximately 1.3-kilobase cDNA revealed one open reading frame that predicts a 332-amino acid protein. In vitro transcription/translation of c15 cDNA resulted in the production of a 45-kilodalton protein. Sequence analysis revealed that the c15 open reading frame contains a potential nuclear localization signal, a very acidic region, and a carboxy-terminal region of 94 amino acids which are 68% identical and 78% similar to the nuclear movement protein, NUDC, found in Aspergillus nidulans. Such a high degree of conservation suggests that the NUDC-like motif in c15 has been conserved through evolution for an important structure and/or function.

Inhibition of prostate tumor growth by overexpression of NudC, a microtubule motor-associated protein

“…NudC was isolated as an early growth-related gene in response to mitogenic stimulation by prolactin, suggesting that its expression is associated with cell proliferation (Axtell et al, 1995;Morris et al, 1997). Consistent with this initial observation, NudC expression is increased in various cell types undergoing mitosis (Gocke et al, 2000a, b) or stimulated to proliferate (Aumais et al, 2000;Gocke et al, 2000a, b), with high levels observed in leukemic cells and tumors (Aumais et al, 2000).…”

“…We previously identified NudC as an early response gene induced in mitogen-stimulated T cells (Axtell et al, 1995). Several studies show that elevated NudC levels correlate with the proliferative status of various cell types, tissues and tumors.…”

“…Several studies show that elevated NudC levels correlate with the proliferative status of various cell types, tissues and tumors. NudC mRNA levels increase during mid-G1 and NudC protein levels double during G2/M phase of the cell cycle (Axtell et al, 1995). NudC expression is elevated in mammalian cells with a high growth rate (Gocke et al, 2000a, b), in clinical bone marrow isolates from patients with acute lymphoblastic or acute myelogenous leukemia (Miller et al, 1999), and in prostate tumors derived from the TRAMP mouse (Aumais et al, 2000).…”

Switching of Platelet-activating Factor Acetylhydrolase Catalytic Subunits in Developing Rat Brain

“…If nuclear migration is essential for neuronal migration, it is reasonable to conclude that a defect in nuclear translocation is the cause of the neuronal migration defect observed in Miller-Dieker lissencephaly. An other gene, nudC, encodes a 22-kDa protein of unknown function, but it shows 68% identity to the C-terminal half of C15 protein, which was originally identified as a prolactin-inducible gene in activated T cells (24). Complementation experiments showed that the full-length mammalian (rat) C15 protein, which has a molecular mass of 45 kDa, is capable of rescuing the nuclear movement defect of nudC mutants (25) that the nudC protein regulates the nudF protein post-transcriptionally, suggesting that nudF and nudC proteins interact within cells.…”

Transcriptional Inhibition by Stat5

“…In Vitro Transcription and Translation (TNT) of Stat5b-Stat5b and Stat5a were transcribed and translated in vitro using the T3 TNTcoupled reticulocyte lysate systems (Promega, Madison, WI) with 40 Ci of [ 35 S]methionine as described previously (25). 5 l of each reaction mixture was resolved by 7.5% SDS-polyacrylamide gel electrophoresis and analyzed by autoradiography to examine the size of Stat5b and Stat5a or used for immunoprecipitation with anti-Stat5b and antiStat5a Abs.…”