Fig. 6

Positive regulatory pathways of PD-L1 mediated by other posttranslational modifications. a PDIA5 appears to exert a negative regulatory effect on PD-L1, while ERO1-a enhances PD-L1 expression by facilitating the proper formation of disulfide bonds in PD-L1. ERO1-α additionally upregulates HIF-1a protein, resulting in increased PD-L1 mRNA and protein levels. b S-palmitoylation occurs within the Golgi apparatus. ZDHHC9, DHHC3, DHHC5, and FASN have been identified as promoters of PD-L1 palmitoylation and thereby contribute to the stabilization of the PD-L1 protein. Conversely, DHA inhibits FASN, thereby suppressing the palmitoylation of PD-L1. c STAT5, which promotes glycolysis, leads to lactic acid accumulation, subsequently facilitating E3BP nuclear translocation and histone lactylation, culminating in the induction of PD-L1 transcription. d HDAC2 facilitates nuclear translocation through PD-L1 deacetylation, whereas p300 promotes acetylation, enhancing its interaction with TRAPPC4 and facilitating PD-L1 recycling to the membrane. e PDGF/ARF6/AMAP1 enhances the recycling of PD-L1 to the membrane by augmenting the ADP-ribosylation of PD-L1. The black arrows denote positive regulation, while the red arrows signify negative regulation