Department of Molecular Medicine, Scripps Research, 120 Scripps Way, Jupiter, Florida 33458-5284, United States.
Department of Chemistry, Scripps Research, 120 Scripps Way, Jupiter, Florida 33458-5284, United States.
ACS Chem Biol. 2021 Oct 15;16(10):1994-2003. doi: 10.1021/acschembio.1c00313. Epub 2021 Jun 28.
Myogenic differentiation, the irreversible developmental process where precursor myoblast muscle stem cells become contractile myotubes, is heavily regulated by glycosylation and glycan-protein interactions at the cell surface and the extracellular matrix. The glycan-binding protein galectin-1 has been found to be a potent activator of myogenic differentiation. While it is being explored as a potential therapeutic for muscle repair, a precise understanding of its glycoprotein interactors is lacking. These gaps are due in part to the difficulties of capturing glycan-protein interactions in live cells. Here, we demonstrate the use of a proximity tagging strategy coupled with quantitative mass-spectrometry-based proteomics to capture, enrich, and identify the glycan-mediated glycoprotein interactors of galectin-1 in cultured live mouse myoblasts. Our interactome dataset can serve as a resource to aid the determination of mechanisms through which galectin-1 promotes myogenic differentiation. Moreover, it can also facilitate the determination of the physiological glycoprotein counter-receptors of galectin-1. Indeed, we identify several known and novel glycan-mediated ligands of galectin-1 as well as validate that galectin-1 binds the native CD44 glycoprotein in a glycan-mediated manner.
肌发生分化是一个不可逆的发育过程，在此过程中，前体细胞肌母细胞肌肉干细胞变成收缩的肌管。该过程受到细胞表面和细胞外基质中糖基化和聚糖-蛋白相互作用的严格调控。现已发现糖结合蛋白半乳糖凝集素-1是肌发生分化的有效激活剂。虽然它被探索作为肌肉修复的一种潜在治疗方法，但对其糖蛋白相互作用体的精确理解却很缺乏。这些空白部分原因是在活细胞中捕获糖蛋白相互作用存在困难。在这里，我们展示了一种临近标记策略的应用，该策略结合了基于定量质谱的蛋白质组学，用于捕获、富集和鉴定培养的活小鼠成肌细胞中半乳糖凝集素-1的糖介导糖蛋白相互作用体。我们的相互作用组数据集可用作资源，以帮助确定半乳糖凝集素-1促进肌发生分化的机制。此外，它还可以促进确定半乳糖凝集素-1的生理糖蛋白对应受体。事实上，我们鉴定了几个已知和新的半乳糖凝集素-1的糖介导配体，并验证了半乳糖凝集素-1以糖介导的方式结合天然的 CD44 糖蛋白。
