PD-1 signaling negatively regulates the common cytokine receptor γ chain via MARCH5-mediated ubiquitination and degradation to suppress anti-tumor immunity.

Combination therapy with PD-1 blockade and IL-2 substantially improves anti-tumor efficacy comparing to monotherapy. The underlying mechanisms responsible for the synergistic effects of the combination therapy remain enigmatic. Here we show that PD-1 ligation results in BATF-dependent transcriptional induction of the membrane-associated E3 ubiquitin ligase MARCH5, which mediates K27-linked polyubiquitination and lysosomal degradation of the common cytokine receptor γ chain (γ).

The membrane-associated ubiquitin ligases MARCH2 and MARCH3 target IL-5 receptor alpha to negatively regulate eosinophilic airway inflammation.

Interleukin 5 (IL-5) plays crucial roles in type 2-high asthma by mediating eosinophil maturation, activation, chemotaxis and survival. Inhibition of IL-5 signaling is considered a strategy for asthma treatment. Here, we identified MARCH2 and MARCH3 as critical negative regulators of IL-5-triggered signaling.

MARCH3 negatively regulates IL-3-triggered inflammatory response by mediating K48-linked polyubiquitination and degradation of IL-3Rα.

Interleukin-3 (IL-3) is a hematopoietic growth factor and critical regulator of inflammatory response such as sepsis. IL-3 binds to IL-3 receptor α (IL-3Rα), which is then associated with IL-3Rβ to initiate signaling. How IL-3-triggered physiological and pathological effects are regulated at the receptor level is unclear.

The membrane-associated E3 ubiquitin ligase MARCH3 downregulates the IL-6 receptor and suppresses colitis-associated carcinogenesis.

The IL-6-STAT3 axis is critically involved in inflammation-associated carcinogenesis (IAC). How this axis is regulated to modulate IAC remains unknown. Here, we show that the plasma membrane-associated E3 ubiquitin ligase MARCH3 negatively regulates STAT3 activation triggered by IL-6, as well as another IL-6 subfamily member, Oncostatin M (OSM).

mTORC1 activity regulates post-translational modifications of glycine decarboxylase to modulate glycine metabolism and tumorigenesis.

Glycine decarboxylase (GLDC) is a key enzyme of glycine cleavage system that converts glycine into one-carbon units. GLDC is commonly up-regulated and plays important roles in many human cancers. Whether and how GLDC is regulated by post-translational modifications is unknown.