Sprouty-2 is an important regulator of growth factor signalling and a tumour suppressor protein. The defining feature of this protein is a cysteine-rich domain (CRD) that contains twenty-six cysteine residues and is modified by S-acylation. In this study, we show that the CRD of sprouty-2 is differentially modified by S-acyltransferase enzymes. The high specificity/low activity zDHHC17 enzyme mediated restricted S-acylation of sprouty-2, and cysteine-265 and -268 were identified as key targets of this enzyme. In contrast, the low specificity/high activity zDHHC3 and zDHHC7 enzymes mediated more expansive modification of the sprouty-2 CRD. Nevertheless, S-acylation by all enzymes enhanced sprouty-2 expression, suggesting that S-acylation stabilises this protein. In addition, we identified two charged residues (aspartate-214 and lysine-223), present on opposite faces of a predicted α-helix in the CRD, which are essential for S-acylation of sprouty-2. Interestingly, mutations that perturbed S-acylation also led to a loss of plasma membrane localisation of sprouty-2 in PC12 cells. This study provides insight into the mechanisms and outcomes of sprouty-2 S-acylation, and highlights distinct patterns of S-acylation mediated by different classes of zDHHC enzymes.

Sprouty-2 是生长因子信号传导的重要调节因子和肿瘤抑制蛋白。该蛋白质的决定性特征是富含半胱氨酸的结构域 (CRD)，其中包含 26 个半胱氨酸残基，并经过 S-酰化修饰。在这项研究中，我们发现 sprouty-2 的 CRD 受到 S-酰基转移酶的差异性修饰。高特异性/低活性 zDHHC17 酶介导 sprouty-2 的限制性 S-酰化，半胱氨酸 265 和 -268 被确定为该酶的关键靶标。相反，低特异性/高活性的 zDHHC3 和 zDHHC7 酶介导 sprouty-2 CRD 的更广泛的修饰。然而，所有酶的 S-酰化都会增强 sprouty-2 的表达，表明 S-酰化可以稳定该蛋白。此外，我们还鉴定了两个带电残基（天冬氨酸 214 和赖氨酸 223），它们存在于 CRD 中预测的 α 螺旋的相对面上，这对于 sprouty-2 的 S 酰化至关重要。有趣的是，扰乱 S-酰化的突变也会导致 PC12 细胞中 sprouty-2 质膜定位的丧失。这项研究深入了解了 sprouty-2 S-酰化的机制和结果，并强调了不同类别的 zDHHC 酶介导的 S-酰化的不同模式。