Chromosome 4 open reading frame 54 (C4orf54)

Chromosome 4 open reading frame 54 (C4orf54) encodes a large, largely uncharacterized human protein of 1,793 amino acids, also referred to as FOPV and LOC285556. The protein is primarily found in the nucleus and cytoplasm, especially in muscle cells and some glands; it is highly enriched in serine and threonine residues and displays post-translational modifications such as myristylation and phosphorylation. C4orf54 is evolutionarily conserved across vertebrates. The protein has no well-defined functional domains but is known to physically interact with BTF3, CUL4A, and KRAS, suggesting possible involvement in regulatory or signaling processes—however, its precise molecular function remains unknown. Clinical evidence indicates that mutations in this gene may be associated with familial obliterative portal venopathy (a rare liver vascular disease), as well as portal hypertension and spinocerebellar ataxia 36. Currently, there are no known drugs directly targeting this protein, and it is not classified as a typical therapeutic target such as a receptor, enzyme, transporter, or transcription factor. There are no established uses as a biomarker or notable safety concerns described in the literature.

Other names

FOPVLOC285556Familial obliterative portal venopathyUncharacterized protein C4orf54