title: CD43 interaction with ezrin-radixin-moesin (ERM) proteins regulates T-cell trafficking and CD43 phosphorylation.
abstract: Cell polarization is a key feature of cell motility, driving cell migration to tissues. CD43 is an abundantly expressed molecule on the T-cell surface that shows distinct localization to the migrating T-cell uropod and the distal pole complex (DPC) opposite the immunological synapse via association with the ezrin-radixin-moesin (ERM) family of actin regulatory proteins. CD43 regulates multiple T-cell functions, including T-cell activation, proliferation, apoptosis, and migration. We recently demonstrated that CD43 regulates T-cell trafficking through a phosphorylation site at Ser-76 (S76) within its cytoplasmic tail. Using a phosphorylation-specific antibody, we now find that CD43 phosphorylation at S76 is enhanced by migration signals. We further show that CD43 phosphorylation and normal T-cell trafficking depend on CD43 association with ERM proteins. Interestingly, mutation of S76 to mimic phosphorylation enhances T-cell migration and CD43 movement to the DPC while blocking ERM association, showing that CD43 movement can occur in the absence of ERM binding. We also find that protein kinase CΘ can phosphorylate CD43. These results show that while CD43 binding to ERM proteins is crucial for S76 phosphorylation, CD43 movement and regulation of T-cell migration can occur through an ERM-independent, phosphorylation-dependent mechanism.
authors.affiliation: Section of Pulmonary and Critical Care Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA. jucannon@salud.unm.edu
authors.forename: J L
authors.initials: JL
authors.lastname: Cannon
authors.forename: P D
authors.initials: PD
authors.lastname: Mody
authors.forename: K M
authors.initials: KM
authors.lastname: Blaine
authors.forename: E J
authors.initials: EJ
authors.lastname: Chen
authors.forename: A D
authors.initials: AD
authors.lastname: Nelson
authors.forename: L J
authors.initials: LJ
authors.lastname: Sayles
authors.forename: T V
authors.initials: TV
authors.lastname: Moore
authors.forename: B S
authors.initials: BS
authors.lastname: Clay
authors.forename: N O
authors.initials: NO
authors.lastname: Dulin
authors.forename: R A
authors.initials: RA
authors.lastname: Shilling
authors.forename: J K
authors.initials: JK
authors.lastname: Burkhardt
authors.forename: A I
authors.initials: AI
authors.lastname: Sperling
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D054992:Immunological Synapses / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D051917:Leukosialin / Q000235:genetics / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D008840:Microfilament Proteins / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D000074121:Protein Kinase C-theta; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000166:cytology / Q000502:physiology*; D000099149:Ezrin
chemical_list: D003598:Cytoskeletal Proteins; D007527:Isoenzymes; D051917:Leukosialin; D008565:Membrane Proteins; D008840:Microfilament Proteins; D011493:Protein Kinase C; D000074121:Protein Kinase C-theta; D011993:Recombinant Fusion Proteins; D000099149:Ezrin; C071058:moesin; C071776:radixin; C489593:Prkcq protein, mouse