CXCR4 : C-X-C motif chemokine receptor 4
Description
The CXCR4 (C-X-C motif chemokine receptor 4) is a protein-coding gene located on chromosome 2.
The CXCR4 gene provides instructions for making a receptor protein that spans the outer membrane of cells, specifically white blood cells and cells in the brain and spinal cord (central nervous system). Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. After attachment of its ligand, called SDF-1, the CXCR4 protein turns on (activates) signaling pathways inside the cell. These pathways help regulate cell growth and division (proliferation), the process by which cells mature to carry out specific functions (differentiation), and cell survival. Once signaling is stimulated, the CXCR4 protein is removed from the cell membrane (internalized) and broken down so it can no longer activate the signaling pathways.The CXCR4 receptor is also involved in the movement (migration) of cells. Cells that have the CXCR4 protein in their membrane are attracted to SDF-1. High levels of this ligand are found in the bone marrow, which helps certain blood cells migrate to and stay in the bone marrow until they are needed elsewhere in the body. Retention of early blood cells known as hematopoietic stem cells in the bone marrow is important to ensure that stem cells are available when needed. White blood cells also remain in the bone marrow until they are needed in the body to fight infection.
CXCR4 is a receptor for the chemokine CXCL12/SDF-1. It signals by increasing intracellular calcium levels and activating MAPK1/MAPK3. This receptor also plays a role in the AKT signaling cascade. CXCR4 is involved in cell migration, for example during wound healing. It acts as a receptor for extracellular ubiquitin, leading to increased intracellular calcium levels and reduced cellular cAMP levels. CXCR4 binds bacterial lipopolysaccharide (LPS) and mediates LPS-induced inflammatory responses, including TNF secretion by monocytes. It is involved in hematopoiesis, cardiac ventricular septum formation, and vascularization of the gastrointestinal tract. CXCR4 also plays a role in cerebellar development and, in the central nervous system, it may mediate hippocampal-neuron survival.
CXCR4 is also known as CD184, D2S201E, FB22, HM89, HSY3RR, LAP-3, LAP3, LCR1, LESTR, NPY3R, NPYR, NPYRL, NPYY3R, WHIM, WHIMS, WHIMS1.
