Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Institute for Biological Instrumentation, Institutskaya str., 7, Pushchino, Moscow Region 142290, Russia.
Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Institute for Biological Instrumentation, Institutskaya str., 7, Pushchino, Moscow Region 142290, Russia.
Cell Calcium. 2024 May;119:102869. doi: 10.1016/j.ceca.2024.102869. Epub 2024 Mar 5.
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic myelopoietic growth factor and proinflammatory cytokine, clinically used for multiple indications and serving as a promising target for treatment of many disorders, including cancer, multiple sclerosis, rheumatoid arthritis, psoriasis, asthma, COVID-19. We have previously shown that dimeric Ca-bound forms of S100A6 and S100P proteins, members of the multifunctional S100 protein family, are specific to GM-CSF. To probe selectivity of these interactions, the affinity of recombinant human GM-CSF to dimeric Ca-loaded forms of 18 recombinant human S100 proteins was studied by surface plasmon resonance spectroscopy. Of them, only S100A4 protein specifically binds to GM-CSF with equilibrium dissociation constant, K, values of 0.3-2 μM, as confirmed by intrinsic fluorescence and chemical crosslinking data. Calcium removal prevents S100A4 binding to GM-CSF, whereas monomerization of S100A4/A6/P proteins disrupts S100A4/A6 interaction with GM-CSF and induces a slight decrease in S100P affinity for GM-CSF. Structural modelling indicates the presence in the GM-CSF molecule of a conserved S100A4/A6/P-binding site, consisting of the residues from its termini, helices I and III, some of which are involved in the interaction with GM-CSF receptors. The predicted involvement of the 'hinge' region and F89 residue of S100P in GM-CSF recognition was confirmed by mutagenesis. Examination of S100A4/A6/P ability to affect GM-CSF signaling showed that S100A4/A6 inhibit GM-CSF-induced suppression of viability of monocytic THP-1 cells. The ability of the S100 proteins to modulate GM-CSF activity is relevant to progression of various neoplasms and other diseases, according to bioinformatics analysis. The direct regulation of GM-CSF signaling by extracellular forms of the S100 proteins should be taken into account in the clinical use of GM-CSF and development of the therapeutic interventions targeting GM-CSF or its receptors.
粒细胞-巨噬细胞集落刺激因子（GM-CSF）是一种多效性的骨髓造血生长因子和前炎性细胞因子，临床上用于多种适应症，并作为治疗多种疾病的有前途的靶点，包括癌症、多发性硬化症、类风湿性关节炎、银屑病、哮喘、COVID-19。我们之前已经表明，属于多功能 S100 蛋白家族的 S100A6 和 S100P 蛋白的二聚体 Ca 结合形式是 GM-CSF 的特异性。为了探究这些相互作用的选择性，通过表面等离子体共振光谱法研究了重组人 GM-CSF 与 18 种重组人 S100 蛋白的二聚体 Ca 负载形式的亲和力。其中，只有 S100A4 蛋白以 0.3-2 μM 的平衡解离常数（K）值特异性结合 GM-CSF，这一点通过本征荧光和化学交联数据得到了证实。钙的去除阻止 S100A4 与 GM-CSF 的结合，而 S100A4/A6/P 蛋白的单体化破坏了 S100A4/A6 与 GM-CSF 的相互作用，并导致 S100P 对 GM-CSF 的亲和力略有下降。结构建模表明，GM-CSF 分子中存在一个保守的 S100A4/A6/P 结合位点，由其末端、螺旋 I 和 III 的残基组成，其中一些残基参与与 GM-CSF 受体的相互作用。通过突变分析证实了 S100P 的“铰链”区域和 F89 残基在 GM-CSF 识别中的预测作用。检查 S100A4/A6/P 对 GM-CSF 信号转导的影响的实验表明，S100A4/A6 抑制 GM-CSF 诱导的单核细胞 THP-1 细胞活力降低。根据生物信息学分析，S100 蛋白调节 GM-CSF 活性与多种肿瘤和其他疾病的进展有关。在 GM-CSF 的临床应用和针对 GM-CSF 或其受体的治疗干预的开发中，应考虑细胞外形式的 S100 蛋白对 GM-CSF 信号转导的直接调节。
