title: Recruitment of activating NK-cell receptors 2B4 and NKG2D to membrane microdomains in mammalian cells is dependent on their transmembrane regions.
abstract: Membrane microdomains play an important role in the regulation of natural killer (NK) cell activities. These cholesterol-rich membrane domains are enriched at the activating immunological synapse and several activating NK-cell receptors are known to localize to membrane microdomains upon receptor engagement. In contrast, inhibitory receptors do not localize in these specialized membrane domains. In addition, the functional competence of educated NK cells correlates with a confinement of activating receptors in membrane microdomains. However, the molecular basis for this confinement is unknown. Here, we investigate the structural requirements for the recruitment of the human-activating NK-cell receptors NKG2D and 2B4 to detergent-resistant membrane fractions in the murine BA/F3 cell line and in the human NK-cell line NKL. This stimulation-dependent recruitment occurred independently of the intracellular domains of the receptors. However, either interfering with the association between NKG2D and DAP10, or mutating the transmembrane region of 2B4 impacted the recruitment of the receptors to detergent-resistant membrane fractions and modulated the function of 2B4 in NK cells. Our data suggest a potential interaction between the transmembrane region of NK-cell receptors and membrane lipids as a molecular mechanism involved in determining the membrane confinement of activating NK-cell receptors.
authors.affiliation: IfADo-Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany.
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Gütgemann
authors.forename: Mina M
authors.initials: MM
authors.lastname: Sandusky
authors.forename: Sabine
authors.initials: S
authors.lastname: Wingert
authors.forename: Maren
authors.initials: M
authors.lastname: Claus
authors.forename: Carsten
authors.initials: C
authors.lastname: Watzl
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology; D008563:Membrane Lipids / Q000276:immunology; D021962:Membrane Microdomains / Q000378:metabolism*; D051379:Mice; D046912:Multiprotein Complexes / Q000276:immunology; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology* / Q000378:metabolism*; D000071176:Signaling Lymphocytic Activation Molecule Family
chemical_list: D015703:Antigens, CD; C084093:CD244 protein, human; C120528:HCST protein, human; C527085:KLRK1 protein, human; D008563:Membrane Lipids; D046912:Multiprotein Complexes; D055655:NK Cell Lectin-Like Receptor Subfamily K; D011971:Receptors, Immunologic; D000071176:Signaling Lymphocytic Activation Molecule Family
keywords: 2B4; Activating receptor; Lipid rafts; Membrane microdomains; NK cells; NKG2D; Signal transduction