INSERM U. 463,
Institut de biologie des hôpitaux de Nantes,
9, quai Moncousu, 44093 Nantes Cedex 01.
Despite their abundant expression in hematopoietic cells, the role played by heterotrimeric G proteins (G proteins) and G protein-coupled receptors (GCR) in the regulation of hematopoiesis remains unappreciated. We have reviewed the current knowledge on expression and functions of the diverse G proteins and GCR of human hematopoietic cells, according to lineage and maturation. There is now mounting evidence that, in addition to stimulating specific functions such as chemotaxis and exocytosis, GCR and G proteins can regulate the proliferation of hematopoietic progenitors. For this function, agonists of GCR and G proteins include molecules as diverse as chemokines, neuropeptides, catecholamines, chronomediators, nucleotides and infectious agents. The molecular pathways activated by GCR and G proteins for the regulation of hematopoiesis are discussed.