VASP is a CXCR2-interacting protein that regulates CXCR2-mediated polarization and chemotaxis.
Chemotaxis regulates the recruitment of leukocytes, which is integral for a number of biological processes and is mediated through the interaction of chemokines with seven transmembrane G-protein-coupled receptors. Several studies have indicated that chemotactic signaling pathways might be activated via G-protein-independent mechanisms, perhaps through novel receptor-interacting proteins. CXCR2 is a major chemokine receptor expressed on neutrophils. We used a proteomics approach to identify unique ligand-dependent CXCR2-interacting proteins in differentiated neutrophil-like HL-60 cells. Using this approach, vasodilator-stimulated phosphoprotein (VASP) was identified as a CXCR2-interacting protein. The interaction between CXCR2 and VASP is direct and enhanced by CXCL8 stimulation, which triggers VASP phosphorylation via PKA- and PKCdelta-mediated pathways. The interaction between CXCR2 and VASP requires free F-actin barbed ends to recruit VASP to the leading edge. Finally, knockdown of VASP in HL-60 cells results in severely impaired CXCR2-mediated chemotaxis and polarization. These data provide the first demonstration that direct interaction of VASP with CXCR2 is essential for proper CXCR2 function and demonstrate a crucial role for VASP in mediating chemotaxis in leukocytes.
Department of Veterans Affairs, Nashville, TN 37212, USA.
Nicole F
NF
Neel
Melanie
M
Barzik
Dayanidhi
D
Raman
Tammy
T
Sobolik-Delmaire
Jiqing
J
Sai
Amy J
AJ
Ham
Raymond L
RL
Mernaugh
Frank B
FB
Gertler
Ann
A
Richmond
D000199:Actins / Q000378:metabolism; D000818:Animals; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity; D002633:Chemotaxis / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D018922:HL-60 Cells; D006801:Humans; D016209:Interleukin-8 / Q000378:metabolism; D007962:Leukocytes / Q000166:cytology / Q000502:physiology*; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011493:Protein Kinase C / Q000378:metabolism; D017434:Protein Structure, Tertiary; D023063:Receptors, Interleukin-8B / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D000098662:Vasodilator-Stimulated Phosphoprotein
D000199:Actins; D015815:Cell Adhesion Molecules; D016209:Interleukin-8; D008840:Microfilament Proteins; D010750:Phosphoproteins; D023063:Receptors, Interleukin-8B; D011993:Recombinant Fusion Proteins; D000098662:Vasodilator-Stimulated Phosphoprotein; D012694:Serine; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C