Transmembrane protein 203 (TMEM203)

Transmembrane protein 203 (TMEM203) is an evolutionarily conserved, multi-pass transmembrane protein primarily localized to the endoplasmic reticulum. TMEM203 is involved in the regulation of intracellular calcium ion homeostasis, maintaining normal endoplasmic reticulum calcium levels, and modulating cellular calcium signaling pathways. In male mice, loss of TMEM203 leads to infertility due to a severe block in spermatogenesis and altered calcium handling in spermatocytes. TMEM203 interacts with key endoplasmic reticulum calcium regulatory proteins, including STIM1, SERCA2, and IP3R. It also acts as a regulator of STING-mediated inflammatory signaling in macrophages, promoting activation of TBK1 kinase and IRF3, leading to increased production of type I interferons. Elevated TMEM203 expression is associated with systemic lupus erythematosus activity, suggesting a role in autoimmune and inflammatory responses[2][3][4][5]. No approved or known drugs are reported to directly target TMEM203.

Other names

MGC14327HBEBP1HBeAg-binding protein 1TMEM203transmembrane protein 203

Modulation of STING-mediated type I interferon production (in immune cells); Regulation of ER calcium homeostasis affecting calcium-dependent cellular signaling