Asymmetrical ligand-induced cross-regulation of chemokine (C-X-C motif) receptor 4 by α1-adrenergic receptors at the heteromeric receptor complex. Sci Rep 2018 Feb 09;8(1):2730
Date
02/11/2018Pubmed ID
29426850Pubmed Central ID
PMC5807542DOI
10.1038/s41598-018-21096-4Scopus ID
2-s2.0-85053764631 (requires institutional sign-in at Scopus site) 17 CitationsAbstract
Recently, we reported that chemokine (C-X-C motif) receptor (CXCR)4 and atypical chemokine receptor 3 regulate α1-adrenergic receptors (α1-AR) through the formation of hetero-oligomeric complexes. Whether α1-ARs also regulate chemokine receptor function within such heteromeric receptor complexes is unknown. We observed that activation of α1b-AR within the α1b-AR:CXCR4 heteromeric complex leads to cross-recruitment of β-arrestin2 to CXCR4, which could not be inhibited with AMD3100. Activation of CXCR4 did not cross-recruit β-arrestin2 to α1b-AR. A peptide analogue of transmembrane domain 2 of CXCR4 interfered with α1b-AR:CXCR4 heteromerization and inhibited α1b-AR-mediated β-arrestin2 cross-recruitment. Phenylephrine (PE) induced internalization of CXCR4 in HEK293 cells co-expressing CXCR4 and α1b-AR and of endogenous CXCR4 in human vascular smooth muscle cells (hVSMC). The latter was detectable despite blockade of CXCR4 with the neutralizing antibody 12G5. hVSMC migrated towards CXCL12 and PE, but not towards a combination of CXCL12 and PE. PE inhibited CXCL12-induced chemotaxis of hVSMC (IC50: 77 ± 30 nM). Phentolamine cross-inhibited CXCL12-induced chemotaxis of hVSMC, whereas AMD3100 did not cross-inhibit PE-induced chemotaxis. These data provide evidence for asymmetrical cross-regulation of CXCR4 by α1-adrenergic receptors within the heteromeric receptor complex. Our findings provide mechanistic insights into the function of α1-AR:CXCR4 heteromers and suggest alternative approaches to modulate CXCR4 in disease conditions.
Author List
Gao X, Albee LJ, Volkman BF, Gaponenko V, Majetschak MAuthor
Brian F. Volkman PhD Professor in the Biochemistry department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
Adrenergic alpha-1 Receptor AgonistsCell Membrane
Cells, Cultured
Chemotaxis
Humans
Ligands
Myocytes, Smooth Muscle
Phenylephrine
Protein Binding
Receptors, Adrenergic, alpha-1
Receptors, CXCR4
Signal Transduction
beta-Arrestins
