Update information. Lysine acetylation and ubiquitination are one of many protein modifications and play a crucial role in the biological regulation of many organisms, but little is known about the relationship between acetylation and ubiquitination few. Here, the Isw1 protein is an important member of the chromatin remodeling complex, and we performed single-protein modification mass spectrometry detection of the C. neoformans Isw1 protein and site mutations for both detected modifications. The data showed that the two modifications of Cryptococcus neoformans Isw1 protein have a balance of each other. Acetylation can maintain protein stability and maintain protein function, while ubiquitination can reduce protein level and maintain Isw1 protein expression. The expression level of Isw1 protein leads to resistance to antifungal drugs. These results reveal the resistance mechanism of Isw1 protein of Cryptococcus neoformans to antifungal drugs.