RING-CH finger, H2 subclass (C4HC3-type), found in membrane-associated RING-CH proteins (MARCH)
The family corresponds to a novel family of membrane-associated E3 ubiquitin ligases, consisting of 11 members in mammals (MARCH1-11), which are characterized by containing an N-terminal C4HC3-type RING-CH finger, also known as vRING or RINGv, a variant of C3H2C3-type RING-H2 finger). Most family members have hydrophobic transmembrane spans and are localized to the plasma membrane and intracellular organelle membrane. Only MARCH7 and MARCH10 are predicted to have no transmembrane spanning region. MARCH proteins have been implicated in mediating the ubiquitination and subsequent down-regulation of cell-surface immune regulatory molecules, such as major histocompatibility complex class II and CD86, as well as in endoplasmic reticulum-associated degradation, endosomal protein trafficking, mitochondrial dynamics, and spermatogenesis.