Nature Biotechnology
21, 1321 - 1327 (2003)
Published online: 12 October 2003; | doi:10.1038/nbt889
A genetic approach to inactivating chemokine receptors using a modified viral proteinV McNeil Coffield1, 3, Qi Jiang3
& Lishan Su1, 2, 31
Curriculum in Genetics and Molecular Biology, School of Medicine, The University of North Carolina, Chapel Hill, NC 27599-7295, USA. 2
Department of Microbiology and Immunology, School of Medicine, The University of North Carolina, Chapel Hill, NC 27599-7295, USA. 3
22-048 Lineberger Cancer Center, School of Medicine, The University of North Carolina, Chapel Hill, NC 27599-7295, USA.
Correspondence should be addressed to Lishan Su lsu@med.unc.eduWe 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.
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