A post-translational modification (PTM) occurs when a nucleophilic residue (e.g., lysine of a target protein) attacks electrophilic substrate molecules (e.g., acyl-AMP), involving writer enzymes or even occurring spontaneously. Traditionally, this phenomenon was thought to be sequence specific; however, recent research suggests that PTMs can also occur in a non-sequence-specific manner confined to a specific location in a cell. In this Opinion, we compile the accumulated evidence of spray-type PTMs and propose a mechanism for this phenomenon based on the exposure level of reactive electrophilic substrate molecules at the active site of the PTM writers. Overall, a spray-type PTM conceptual framework is useful for comprehending the promiscuous PTM writer events that cannot be adequately explained by the traditional concept of sequence-dependent PTM events.

中文翻译：

---

喷雾型修饰：翻译后修饰的新兴范例

当亲核残基（例如，靶蛋白的赖氨酸）攻击亲电子底物分子（例如，酰基-AMP）时，翻译后修饰（PTM）发生，涉及写入酶甚至自发发生。传统上，这种现象被认为是序列特异性的。然而，最近的研究表明，PTM 也可以以非序列特异性的方式发生，仅限于细胞中的特定位置。在本意见中，我们汇集了喷雾型 PTM 的累积证据，并根据 PTM 编写器活性位点的反应性亲电底物分子的暴露水平提出了这种现象的机制。总体而言，喷雾型 PTM 概念框架有助于理解混杂的 PTM 编写器事件，而传统的序列相关 PTM 事件概念无法充分解释这些事件。