Chemokine Receptor 4

Chemokine (Chemoattractant Cytokines) are small peptides that are potent activators and chemo-attractants for leukocyte subpopulations and other nonhemopoietic cells.  Chemokine receptors (CXCR) belong to the super-family of G protein-coupled receptors (GPCR), which regulate the trafficking and activation of leukocytes, and operate as co-receptors in the entry of HIV-1 and directing the proliferation and migration of immature neurons, glia and their precursors (1). Furthermore, chemokine receptors participate in the etiology and progression of various brain disorders, including AIDS dementia, neuro-inflammatory disease and neuroplasia, making them important potential therapeutic targets in these cases.  Induction of chemokines and infiltration of chemokine receptor-bearing cells has also been shown in a variety of animal models of renal diseases, as well as in human diseases and allograft rejection (2)

	Type	Cat #	Expression
1	CXCR1	CXC-101AP	Melanoma, leukocytes, microglia, EC, podocytes
2	CXCR2	CXC-201AP	Intestinal microvascular cells
3	CXCR3	CXC-301AP	Microglia, podocytes
4	CXCR4	CXC-401AP	Inflammatory cells
5	CXCR5	CXC-501AP	Podocytes,

 

Activation of naïve T cells by specific antigen and cytokines, up-regulate cell adhesion molecules (CAM) as well as chemokine receptors on their surface, which directs them to migrate towards the inflamed tissues.  Several subtypes of CXCR have been characterized (Table1).

CXCR4 is the receptor for the stromal cell derived factor 1(SDF1), that has essential functions on embryo organogenesis, immunological functions and T lymphocyte trafficking. The CXCR4 is identified as a co-factor required for the entry of lymphotropic HIV isolates n CD4+ T lymphocytes (1).  The CXCR4 gene contains two exons separated by an intronic sequence. A 2.6 kb 5’-flanking region located upstream the CXCR4 open reading frame contains a TATA box and the transcription start site characteristic of a functional promoter.  This region also has binding motifs for different transcription factors associated with hemopoiesis and lymphocyte development (3). 

The CXCR4 receptor protein is approximately 45kDa (360 amino acids) protein which has 7 transmembrane domains, characteristic of G-protein coupled receptors.  The all CXCR sequence analyses suggest the presence of 7 transmembrane domains, a characteristic feature of GPCR.  The protein has putative N-glycosylation sites near the extra cellular N-terminal end of the proteins.  The protein has a large 3^rd intra cellular loop which interacts with G-proteins.  The short carboxy terminal is intracellular and has putative post-translational sites.  The Anti-CXCR-selective antibodies were generated against conserved but unique sequences on various CXCR receptors that are expressed only in a particular CXCR receptor subtype.  The polyclonal antibodies were affinity purified on an immobilized antigen based affinity chromatography.  These epitope-specific antibodies strongly label particular chemokine receptors in their respective western blot positive controls.  Anti-CXCR-selective antibodies are also available in the form of fluorescent conjugates for direct application in IHC upon request at extra charge. FabGennix Int. Inc. also provides antibodies against several other GPCRs including orphan receptors.  FabGennix, Inc., will also provide Western blot positive controls for most of these antibodies in ready-to-use buffer for easy identification of respective proteins.  Limited quantities of antigenic peptides are also available.  Please enquire for their availability before ordering.

For research use only, not for diagnostic or therapeutic use.