Translational Glycobiology Institute, Department of Cellular and Molecular Medicine, Herbert Wertheim College of Medicine, Florida International University, Miami, Florida 33199, United States.
Fischell Department of Bioengineering, University of Maryland, College Park, College Park, Maryland 20742, United States.
J Proteome Res. 2024 Aug 2;23(8):3469-3483. doi: 10.1021/acs.jproteome.4c00141. Epub 2024 Jul 15.
Fcγ-receptors (FcγRs) including FcγRII (CD32) gene family members are expressed on leukocytes, bind the crystallizable fragment (Fc) region of immunoglobulin G (IgG), and bridge humoral and cellular immunity. FcγRIIA and FcγRIIB have opposing roles, with the former responsible for activation and the latter for inhibition of immune cell signaling and effector functions. The extracellular domains of human and murine FcγRIIs share multiple conserved glycosylation sites. Understanding the role(s) of FcγRIIA and FcγRIIB glycosylation in autoimmune diseases is precluded by a lack of effective methods to study disease-associated changes in glycosylation. To address this barrier, we developed a method to assess site-specific glycosylation of human FcγRIIA and FcγRIIB, and the mouse ortholog of human FcγRIIB. Among the receptors, conserved glycosylation sites are compared, with the N144/145 site displaying predominantly complex glycans in recombinant FcγRIIs. Differences in sialylation between recombinant human FcγRIIA H/R134 (H/R131) variants at a nearby N145 -glycosylation site are reported. Further, a potential human FcγRIIA -glycosylation site, S179 (S212), is reported in recombinant FcγRIIA. The robust method to assess site-specific glycosylation of FcγRIIs reported here, can be utilized to study the potential role of FcγRII family glycosylation in disease. Data are available via ProteomeXchange with identifier PXD049429.
Fcγ 受体（FcγR）包括 FcγRII（CD32）基因家族成员，表达于白细胞上，能结合免疫球蛋白 G（IgG）的可结晶片段（Fc）区域，并连接体液免疫和细胞免疫。FcγRIIA 和 FcγRIIB 具有相反的作用，前者负责激活，后者负责抑制免疫细胞信号和效应功能。人和鼠 FcγRIIs 的细胞外结构域具有多个保守的糖基化位点。由于缺乏研究疾病相关糖基化变化的有效方法，因此无法了解 FcγRIIA 和 FcγRIIB 糖基化在自身免疫性疾病中的作用。为了解决这一障碍，我们开发了一种评估人 FcγRIIA 和 FcγRIIB 以及人 FcγRIIB 小鼠同源物的特定位点糖基化的方法。在这些受体中，保守的糖基化位点被比较，N144/145 位点在重组 FcγRII 中主要显示复杂糖。报道了附近 N145 糖基化位点的人 FcγRIIA H/R134（H/R131）变体的唾液酸化差异。此外，还报道了重组 FcγRIIA 中的一个潜在人 FcγRIIA 糖基化位点 S179（S212）。这里报道的评估 FcγRII 特定位点糖基化的稳健方法可用于研究 FcγRII 家族糖基化在疾病中的潜在作用。数据可通过 ProteomeXchange 以标识符 PXD049429 获取。
