title: Hematopoietic-specific Rho GTPases Rac2 and RhoH and human blood disorders.
abstract: The small guanosine triphosphotases (GTPases) Rho proteins are members of the Ras-like superfamily. Similar to Ras, most Rho GTPases cycle between active GTP-bound, and inactive GDP-bound conformations and act as molecular switches that control multiple cellular functions. While most Rho GTPases are expressed widely, the expression of Rac2 and RhoH are restricted to hematopoietic cells. RhoH is an atypical GTPase that lacks GTPase activity and remains in the active conformation. The generation of mouse knock-out lines has led to new understanding of the functions of both of these proteins in blood cells. The phenotype of these mice also led to the identification of mutations in human RAC2 and RHOH genes and the role of these proteins in immunodeficiency diseases. This review outlines the basic biology of Rho GTPases, focusing on Rac and RhoH and summarizes human diseases associated with mutations of these genes.
authors.affiliation: Clinic for Pediatric Oncology, Hematology and Clinical Immunology, Heinrich Heine University Duesseldorf, Moorenstreet 5, 40225 Duesseldorf, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Troeger
authors.forename: David A
authors.initials: DA
authors.lastname: Williams
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D005786:Gene Expression Regulation; D006402:Hematologic Diseases / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D006410:Hematopoiesis / Q000235:genetics; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D022423:Myeloid Cells / Q000378:metabolism* / Q000473:pathology; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D020744:rac GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000097766:RAC2 GTP-Binding Protein
chemical_list: D000199:Actins; D014157:Transcription Factors; D020744:rac GTP-Binding Proteins; D020741:rho GTP-Binding Proteins; D000097766:RAC2 GTP-Binding Protein; C447841:RhoH protein, human
keywords: Cytoskeleton; Hematopoiesis; Rac; Rho GTPases; RhoH