Crosstalk between multiple PTM sites on the same protein  A. Distribution of the sequence distance between different PTM sites for proteins in the unregulated, Syn, Hetero-s, and Hetero-h groups. B. Distribution of the number of interacting proteins for proteins in the unregulated, Single, Syn, and Hetero groups. The number of interacting proteins was acquired from IntAct. C. Distribution of the number of identified PTM sites for each protein in unregulated, Single, Syn, and Hetero groups. In (A–C), the lower, median, and upper lines in each violin plot correspond to 25%, 50%, and 75%, respectively. D. Heatmap indicating all relationships between different proteomes including three types of PTM proteomes and WCP. E. Selected proteins in RAW264.7 cells belonging to the important combined PTM types listed in (D). The solid line represents a fast-regulated event and the dotted line represents a slow-regulated event. The number next to the line represents the positon of the PTM site on the corresponding protein. The PTM on the left of “≫” represents the slow-type PTM and the PTM on the right of “≫” represents the fast-type PTM. Hetero-s, synchronous PTM site in heterochronous protein; Hetero-h, heterochronous PTM site in heterochronous protein; Single, single-regulated protein.