Barnes N C, Powell M S, Trist H M, Gavin A L, Wines B D, Hogarth P M
Helen Macpherson Smith Trust Inflammatory Disease Laboratory, The Austin Research Institute, Austin Health, Studley Road, Heidelberg, Vic. 3084, Australia.
Immunol Lett. 2006 Apr 15;104(1-2):118-23. doi: 10.1016/j.imlet.2005.11.007. Epub 2005 Dec 5.
Ligand-dependent aggregation of FcgammaRIIa initiates multiple biochemical processes including the translocation to detergent resistant membrane domains (DRMs) and receptor tyrosine phosphorylation. Palmitoylation of cysteine residues is considered to be one process that assists in the localisation of proteins to DRMs. Within the juxtamembrane region of FcgammaRIIa there is cysteine residue (C208) that we show to be palmitoylated. Mutation of this cysteine residue results in the disruption of FcgammaRIIa translocation to DRMs as empirically defined by insolubility at high Triton X-100 concentrations. This study also demonstrates that the lack of lipid raft association diminishes FcgammaRIIa signaling as measured by receptor phosphorylation and calcium mobilisation functions suggesting that FcgammaRIIa signaling is partially dependent on lipid rafts.
FcγRIIa的配体依赖性聚集引发了多个生化过程，包括向抗去污剂膜结构域（DRM）的转位以及受体酪氨酸磷酸化。半胱氨酸残基的棕榈酰化被认为是协助蛋白质定位到DRM的一个过程。在FcγRIIa的近膜区域存在一个半胱氨酸残基（C208），我们发现它会发生棕榈酰化。该半胱氨酸残基的突变导致FcγRIIa向DRM的转位受到破坏，这是通过在高浓度Triton X-100下的不溶性经验性定义的。这项研究还表明，如通过受体磷酸化和钙动员功能所测量的，缺乏脂筏关联会减少FcγRIIa信号传导，这表明FcγRIIa信号传导部分依赖于脂筏。
