Membrane-associated RING-CH-type finger protein 1 (MARCHF1)

Membrane-associated RING-CH-type finger protein 1 (MARCHF1) is an E3 ubiquitin-protein ligase localized to cellular membranes, particularly in antigen-presenting and immune-regulatory cells[1][3][7]. It catalyzes the transfer of ubiquitin to substrate proteins—most notably MHC class II molecules, CD86, FAS, transferrin receptor (TFRC), and the insulin receptor—marking them for internalization and lysosomal degradation[1][3][7]. This process modulates the surface expression of immune receptors and is especially critical for controlling antigen presentation, immune signaling, and maintaining self-tolerance—regulating both adaptive and innate immune responses[2][5]. MARCHF1 is associated with certain immunodeficiency syndromes and human cytomegalovirus infection, reflecting its role in immune system regulation[1]. It also influences systemic metabolism by controlling insulin receptor levels[6]. The enzyme’s dysregulation could potentially contribute to immune-related diseases and infections, as well as impact tumor surveillance and metabolic homeostasis[1][5][6]. MARCHF1's principal molecular function is via a RING-CH-type zinc finger domain that is essential for its E3 ligase activity, distinguishing it within the RING finger family of E3 ubiquitin ligases[7]. No specific drugs are currently known to target MARCHF1 directly, and no established companion biomarkers are in clinical use, though MHC class II and CD86 surface levels act as functional readouts of its biological activity[2].

Other names

MARCH1MARCH-IRNF171E3 ubiquitin-protein ligase MARCHF1Membrane-associated ring finger protein 1Membrane-associated RING-CH protein IMembrane-associated ring finger (C3HC4) 1RING-type E3 ubiquitin transferase MARCHF1

Ubiquitin ligase activity (modifies lysines on substrate proteins with ubiquitin, targeting them for endocytic internalization and degradation)