title: A genetic approach to inactivating chemokine receptors using a modified viral protein.
abstract: We have developed a genetic system, called degrakine, that specifically and stably inactivates chemokine receptors (CKR) by redirecting the ability of the HIV-1 protein, Vpu, to degrade CD4 in the endoplasmic reticulum (ER) via the host proteasome machinery. To harness Vpu's proteolytic targeting capability to degrade new receptors, we fused a chemokine with the C terminal region of Vpu. The fusion protein, or degrakine, accumulates in the ER, trapping and functionally inactivating its target CKR. We have demonstrated that degrakines based on SDF-1 (CXCL12), MDC (CCL22) and RANTES (CCL5) specifically inactivate their respective receptor functions. Using a retroviral vector expressing the SDF-1 degrakine, we have established that CXCR4 is required for the homing of hematopoietic stem/progenitor cells (HSPC) to the bone marrow immediately after transplantation. Thus the degrakine provides an effective genetic tool to dissect receptor functions in a number of biological systems in vitro and in vivo.
authors.affiliation: Curriculum in Genetics and Molecular Biology, and 22-048 Lineberger Cancer Center, School of Medicine, The University of North Carolina, Chapel Hill, NC 27599-7295, USA.
authors.forename: V McNeil
authors.initials: VM
authors.lastname: Coffield
authors.forename: Qi
authors.initials: Q
authors.lastname: Jiang
authors.forename: Lishan
authors.initials: L
authors.lastname: Su
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D018925:Chemokines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D016503:Drug Delivery Systems / Q000379:methods*; D004721:Endoplasmic Reticulum / Q000276:immunology / Q000378:metabolism; D018390:Gene Targeting / Q000379:methods*; D054298:Human Immunodeficiency Virus Proteins; D006801:Humans; D051379:Mice; D010000:Osteitis / Q000276:immunology / Q000378:metabolism; D015202:Protein Engineering / Q000379:methods; D019707:Receptors, Chemokine / Q000276:immunology* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000276:immunology / Q000378:metabolism; D054334:Viral Regulatory and Accessory Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D000086082:Viroporin Proteins
chemical_list: D018925:Chemokines; D054298:Human Immunodeficiency Virus Proteins; D019707:Receptors, Chemokine; D011993:Recombinant Fusion Proteins; D054334:Viral Regulatory and Accessory Proteins; C514859:vpu protein, Human immunodeficiency virus 1; D000086082:Viroporin Proteins