The role of chemokine activation of Rac GTPases in hematopoietic stem cell marrow homing, retention, and peripheral mobilization.
Signaling downstream from the chemokine receptor CXCR4, the tyrosine kinase receptor c-kit and beta1-integrins has been shown to be crucial in the regulation of migration, homing, and engraftment of hematopoietic stem cells and progenitors. Each of these receptors signal through Rac-type Rho guanosine triphosphatases (GTPases). Rac GTPases play a major role in the organization of the actin cytoskeleton and also in the control of gene expression and the activation of proliferation and survival pathways. Here we review the specific roles of the members of the Rac subfamily of the Rho GTPase family in regulating the intracellular signaling of hematopoietic cells responsible for regulation of homing, marrow retention, and peripheral mobilization.
Cancelas
Jose A
JA
Division of Experimental Hematology, Cincinnati Children's Research Foundation, Cincinnati, Ohio 45215, USA.
Jansen
Michael
M
Williams
David A
DA
D000818:Animals; D002465:Cell Movement; D018925:Chemokines / Q000502:physiology*; D006410:Hematopoiesis; D019650:Hematopoietic Stem Cell Mobilization; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D015398:Signal Transduction; D020744:rac GTP-Binding Proteins / Q000502:physiology*; D020830:rac1 GTP-Binding Protein / Q000502:physiology*; D000097766:RAC2 GTP-Binding Protein
D018925:Chemokines; D020744:rac GTP-Binding Proteins; D020830:rac1 GTP-Binding Protein; D000097766:RAC2 GTP-Binding Protein; C411563:RAC3 protein, human