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Updated: Aug 18, 2026

Direct Induction of Hemogenic Endothelium and Blood by Overexpression of Transcription Factors in Human Pluripotent Stem Cells
Published on: December 3, 2015
A hemopoietic specific gene encoding a small GTP binding protein is overexpressed during T cell activation
L Reibel1, O Dorseuil, R Stancou
1Institut Cochin de Génétique Moléculaire, INSERM U. 257, Paris, France.
Abstract:
We have isolated, from a human B cell line cDNA library, a cDNA (Gx) encoding a small G protein identical to rac 2, a member of the ras superfamily. Gx/rac 2 gene is expressed as a unique mRNA of 1,7 Kb in peripheral blood lymphocytes, in purified B and T cells, in thymus as well as in several B and T cell lines. It is not expressed in many other tissues analysed including liver, brain, lung, heart and kidney. Upon in vitro stimulation with phytohemagglutinin A, peripheral blood lymphocytes show a clear increase of the Gx/rac 2 mRNA after 6 hours; a 30-50 fold accumulation is reached at 24 hours and persists thereafter. Purified T lymphocytes exhibit a similar increase in Gx/rac 2 mRNA expression upon mitogenic stimulation. Therefore, the expression of the Gx/rac 2 gene appears to be restricted to cells of the hemopoietic lineage and to be strongly stimulated during T cell activation. Gx/rac 2 protein must fulfill a specific role in activated T cells that could provide a new model for studying the function of small G proteins.
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