赤血球膜タンパク質のパルミチン酸を自由に回転させることは、脂質ラフトのスペクトリン骨格への固定に責任を負いません。

赤血球脂質ラフトは、基礎となるスペクトリン膜骨格に固定されています[A.Ciana、C。Achilli、C。Balduini、G。Minetti、脂質ラフトと人間の赤血球、バイオチムのスペクトリン骨格との関連について。生物生物。Acta 1808（2011）183-190]。この連鎖の性質と関係する分子はよく理解されていません。相互作用は、炭酸塩によって誘導されるpHおよびイオン強度の増加に敏感です。Given the role of palmitoylation in modulating the partitioning of certain proteins between various sub-cellular compartments and the plasma membrane, we asked whether palmitoylation of p55, a peripheral protein located at the junctional complex between spectrin-actin-protein 4.1 that anchors the membrane skeleton to the lipid bilayer via the transmembrane protein glycophorin C, could脂質ラフトの膜骨格への固定に貢献します。オメガアルキニル基を含む脂肪酸の生物系統化化学類似体に基づいて、タンパク質パルミトイル化を研究するための新しい非放射性方法を採用し、代謝的に細胞タンパク質を標識し、それを代謝して、Azide-Conteaning Reporter Tagのアルキニル病の「クリック化学」反応によって明らかになります。p55の膜局在とパルミトイル化レベルが炭酸塩処理後に変化しなかったことを示します。2つの既知のパルミトイル化阻害剤である2-ブロモポールミチン酸塩とセルレニンは、p55パルミトイル化を完全に阻害し、タンパク質パルミトイルチオエステラーゼ-1（PPT1）（PPT1）は、脂質ラフトと膜皮質の関連性に影響を与えることなく、それを減少させました。脂質ラフトの膜角骨格への結合の。

Erythrocyte lipid rafts are anchored to the underlying spectrin membrane skeleton [A. Ciana, C. Achilli, C. Balduini, G. Minetti, On the association of lipid rafts to the spectrin skeleton in human erythrocytes, Biochim. Biophys. Acta 1808 (2011) 183-190]. The nature of this linkage and the molecules involved are poorly understood. The interaction is sensitive to the increase in pH and ionic strength induced by carbonate. Given the role of palmitoylation in modulating the partitioning of certain proteins between various sub-cellular compartments and the plasma membrane, we asked whether palmitoylation of p55, a peripheral protein located at the junctional complex between spectrin-actin-protein 4.1 that anchors the membrane skeleton to the lipid bilayer via the transmembrane protein glycophorin C, could contribute to the anchoring of lipid rafts to the membrane skeleton. We adopted a new, non-radioactive method for studying protein palmitoylation, based on bio-orthogonal chemical analogues of fatty acids, containing an omega-alkynyl group, to metabolically label cell proteins, which are then revealed by a "click chemistry" reaction of the alkynyl moiety with an azide-containing reporter tag. We show that the membrane localization and palmitoylation levels of p55 did not change after carbonate treatment. 2-bromopalmitate and cerulenin, two known palmitoylation inhibitors, completely inhibited p55 palmitoylation, and protein palmitoyl thioesterase-1 (PPT1) reduced it, without affecting the association between lipid rafts and membrane-skeleton, indicating, on the one hand, that p55 palmitoylation is enzymatic, and, on the other, that it is not involved in the modulation of the linkage of lipid rafts to the membrane-skeleton.