Catalog # CP4251

CXCR4 (Ser-324/Ser-325), phospho-specific Antibody

Rabbit Polyclonal

Application / Dilution

Size 100 μl

Species Reactivity Hu, Rt, Ms, Ck

MW 45 kDa



The chemokine receptor CXCR4 is a widely expressed G protein-coupled receptor required for development, hematopoiesis, organogenesis, and vascularization. In disease, CXCR4 has been implicated in WHIM syndrome, HIV, and cancers. Regulation of CXCR4 function occurs through phosphorylation at multiple sites in the C-terminal region. These sites have been shown to be phosphorylated after CXCL12 stimulation, and involve several kinases, such as PKC and GRK kinases. After CXCL12 stimulation of HEK293 cells, Ser-324 and Ser-325 become phosphorylated by PKC and GRK6, while Ser-330 and Ser-339 are phosphorylated by only GRK6. In human astroglia cells, Ser-324 and Ser-325 are rapidly phosphorylated in endogenous CXCR4, while Ser-330 was phosphorylated with slower kinetics. In addition, arrestin binding to CXCR4 is driven by this phosphorylation of far C-terminal residues. Thus, site-specific phosphorylation of CXCR4 may be regulated by multiple kinases leading to complex regulation of CXCR4 signaling.


Busillo, J. M. et al. (2010) J Biol Chem. 285(10):7805.
Bhandari, D. et al. (2009) Mol Biol Cell. 20:1324.
Orsini, M.J. et al. (2000) J Biol Chem. 275(33):25876.
Orsini, M.J. et al. (1999) J Biol Chem. 274(43):31076.

Western blot analysis of human Jurkat cells treated with 100 nM calyculin A for 30 min. then the blots were untreated (-) or treated (+) with lambda phosphatase. The blots were probed with rabbit polyclonals anti-CXCR4 (Ser-324/Ser-325) (left panel) or anti-CXCR4 (a.a. 322-329) (right panel).

Immunocytochemical labeling of CXCR4 in chick pluripotent cells. The cells were labeled with rabbit polyclonal CXCR4 (S324/S325) antibody (CP4251), then detected using appropriate secondary antibody (Red). (Image provided by Dr. Yangqing Lu at the Regenerative Bioscience Center, University of Georgia).

Phospho-CXCR4 (Ser-324/Ser-325) synthetic peptide (coupled to carrier protein) corresponds to amino acids surrounding Ser-324 and Ser-325 in the C-terminal region of human CXCR4. This sequence is conserved in mouse, rat, and chicken CXCR4, but has low homology to other CXCR family members.

*For more information, see UniProt Accession P61073
Rabbit polyclonal, affinity-purified antibody is supplied in 100µl phosphate-buffered saline, 50% glycerol, 1 mg/ml BSA, and 0.05% sodium azide. Store at –20°C. Stable for 1 year.

The products are are safely shipped at ambient temperature for both domestic and international shipments. Each product is guaranteed to match the specifications as indicated on the corresponding technical data sheet. Please store at -20C upon arrival for long term storage.

The antibody detects bands at 35, 42, 50, and 100 kDa* corresponding to various post-translationally modified forms of CXCR4 on SDS-PAGE immunoblots of human Jurkat and PC3 cells stimulated with calyculin A. These bands co-migrate with similar bands detected with anti-CXCR4 (a.a. 322-329) and anti-CXCR4 (a.a. 328-338) antibodies.

*All molecular weights (MW) are confirmed by comparison to Bio-Rad Rainbow Markers and to western blot mobilities of known proteins with similar MW.

This kit contains: