Relief of cyclin A gene transcriptional inhibition during activation of human primary T lymphocytes via CD2 and CD28 adhesion molecules

Oncogene
A PletJ M Blanchard

Abstract

Cyclin A transcription is cell cycle regulated and induced by cell proliferative signals. To understand the mechanisms underlined in this regulation in normal human cells, we have analysed in vivo protein-DNA interactions at the Cyclin A locus in primary T lymphocytes. Stimulation of purified T lymphocytes by a combination of monoclonal antibodies directed at CD2 and CD28 adhesion molecules gives rise to a long lasting proliferation in the absence of accessory cells. Cyclin A was observed after 4 days of costimulation with anti CD2 + CD28 whereas stimulation by anti CD2 or anti CD28 alone was not effective. In vivo genomic DMS footprinting revealed upstream of the major transcription initiation sites, the presence of at least three protein binding sites, two of which were constitutively occupied. They bind in vitro respectively ATF-1 and NF-Y proteins. The third site was occupied in quiescent cells or in cells stimulated by anti CD2 or anti CD28 alone. The mitogenic combination of anti CD2 + anti CD28 released the footprint as cells were committed to proliferation. Consistent with theses results, nuclear extracts prepared from quiescent cells formed a specific complex with this element, whereas extracts prepared from cells trea...Continue Reading

Citations

Apr 3, 2001·Molecular and Cellular Biology·L FajasM L Vignais
Jan 26, 2006·Oncogene·C AlabertM-L Vignais
Feb 1, 2005·Virus Research·G Joan GrindlayVincent O'Brien
Dec 22, 1999·The Tohoku Journal of Experimental Medicine·T KudoS Matsuno
Dec 22, 1999·Oncogene·A PhilipsJ M Blanchard

❮ Previous
Next ❯

Related Concepts

Related Feeds

Cell Cycle Pathways

Cell cycle is a complex process regulated by several signal transduction pathways and enzymes. Here is the latest research on regulation of cell cycle and cell cycle pathways.

Cell Checkpoints & Regulators

Cell cycle checkpoints are a series of complex checkpoint mechanisms that detect DNA abnormalities and ensure that DNA replication and repair are complete before cell division. They are primarily regulated by cyclins, cyclin-dependent kinases, and the anaphase-promoting complex/cyclosome. Here is the latest research.