cxcl12 and [n33a]cxcl12 in 5637 and hela cells regulating her1 phosphorylation via calmodulincalcineurincxcl12和[n33a]cxcl12和5637年海拉细胞调节通过calmodulincalcineurin her1磷酸化.pdfVIP

CXCL12 and [N33A]CXCL12 in 5637 and HeLa Cells: Regulating HER1 Phosphorylation via Calmodulin/ Calcineurin 1. 1. 2 1 1 Antonella Rigo , Michele Gottardi , Ernesto Damiani , Massimiliano Bonifacio , Isacco Ferrarini , 3 1 Pierluigi Mauri , Fabrizio Vinante * 1 Department of Medicine, Section of Hematology, University of Verona, Verona, Italy, 2 Department of Experimental Biomedical Sciences, University of Padua, Padua, Italy, 3 Proteomics and Metabolomics Unit, Institute for Biomedical Technologies, CNR, Milan, Italy Abstract In the human neoplastic cell lines 5637 and HeLa, recombinant CXCL12 elicited, as expected, downstream signals via both G-protein-dependent and b-arrestin-dependent pathways responsible for inducing a rapid and a late wave, respectively, of ERK1/2 phosphorylation. In contrast, the structural variant [N33A]CXCL12 triggered no b-arrestin-dependent phosphor- ylation of ERK1/2, and signaled via G protein-dependent pathways alone. Both CXCL12 and [N33A]CXCL12, however, generated signals that transinhibited HER1 phosphorylation via intracellular pathways. 1) Prestimulation of CXCR4/HER1- positive 5637 or HeLa cells with CXCL12 modified the HB-EGF-dependent activation of HER1 by delaying the peak phosphorylation of tyrosine 1068 or 1173. 2) Prestimulation with the synthetic variant [N33A]CXCL12, while preserving CXCR4-related chemotaxis and CXCR4 internalization, abolished HER1 phosphorylation. 3) In cells knockdown of b-arrestin 2, CXCL12 induced a full inhibition of HER1 like [N33A]CXCL12 in non-silenced cells. 4) HER1 phosphorylation was restored as usual by inhibiting PCK,